diff --git a/checkstyle-suppressions.xml b/checkstyle-suppressions.xml
index 5f632c578..82e964658 100644
--- a/checkstyle-suppressions.xml
+++ b/checkstyle-suppressions.xml
@@ -5,5 +5,20 @@
   "https://checkstyle.org/dtds/suppressions_1_2.dtd">
 
 <suppressions>
-    <suppress checks="Javadoc" files="."/>
+  <!-- Suppress Javadoc paragraph formatting (empty line before <p> tag) globally. This is a
+       stylistic check that would require fixing hundreds of locations. We still enforce that
+       public APIs have documentation via other Javadoc checks. -->
+  <suppress checks="JavadocParagraph" files="."/>
+
+  <!-- Suppress all Javadoc checks for internal implementation packages -->
+  <suppress checks="Javadoc" files=".*[/\\]internal[/\\].*"/>
+
+  <!-- Suppress all Javadoc checks for example code -->
+  <suppress checks="Javadoc" files=".*[/\\]examples[/\\].*"/>
+
+  <!-- Suppress all Javadoc checks for benchmark code -->
+  <suppress checks="Javadoc" files=".*[/\\]benchmarks[/\\].*"/>
+
+  <!-- Suppress all Javadoc checks for integration tests -->
+  <suppress checks="Javadoc" files=".*[/\\]integration-tests[/\\].*"/>
 </suppressions>
diff --git a/pom.xml b/pom.xml
index 4e3018de8..82aa11862 100644
--- a/pom.xml
+++ b/pom.xml
@@ -234,6 +234,8 @@
           <excludes>
             <exclude>**/generated/**</exclude>
             <exclude>**/*BlockingRejectedExecutionHandler*</exclude>
+            <exclude>**/*AllocationCountingNotificationListener*</exclude>
+            <exclude>**/*MapperConfig*</exclude>
           </excludes>
         </configuration>
         <executions>
@@ -264,6 +266,11 @@
                       <value>COVEREDRATIO</value>
                       <minimum>${jacoco.line-coverage}</minimum>
                     </limit>
+                    <limit>
+                      <counter>BRANCH</counter>
+                      <value>COVEREDRATIO</value>
+                      <minimum>0.50</minimum>
+                    </limit>
                   </limits>
                 </rule>
               </rules>
diff --git a/prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/ExporterOpenTelemetryPropertiesTest.java b/prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/ExporterOpenTelemetryPropertiesTest.java
index 4a2aefe1e..003fba0e6 100644
--- a/prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/ExporterOpenTelemetryPropertiesTest.java
+++ b/prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/ExporterOpenTelemetryPropertiesTest.java
@@ -1,6 +1,7 @@
 package io.prometheus.metrics.config;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 
 import java.util.HashMap;
 import java.util.Map;
@@ -68,4 +69,40 @@ void builder() {
             .build();
     assertValues(properties);
   }
+
+  @Test
+  void builderWithHttpProtobuf() {
+    ExporterOpenTelemetryProperties properties =
+        ExporterOpenTelemetryProperties.builder().protocol("http/protobuf").build();
+    assertThat(properties.getProtocol()).isEqualTo("http/protobuf");
+  }
+
+  @Test
+  void builderWithInvalidProtocol() {
+    assertThatExceptionOfType(IllegalArgumentException.class)
+        .isThrownBy(() -> ExporterOpenTelemetryProperties.builder().protocol("invalid"))
+        .withMessage("invalid: Unsupported protocol. Expecting grpc or http/protobuf");
+  }
+
+  @Test
+  void builderWithInvalidIntervalSeconds() {
+    assertThatExceptionOfType(IllegalArgumentException.class)
+        .isThrownBy(() -> ExporterOpenTelemetryProperties.builder().intervalSeconds(0))
+        .withMessage("0: Expecting intervalSeconds > 0");
+
+    assertThatExceptionOfType(IllegalArgumentException.class)
+        .isThrownBy(() -> ExporterOpenTelemetryProperties.builder().intervalSeconds(-1))
+        .withMessage("-1: Expecting intervalSeconds > 0");
+  }
+
+  @Test
+  void builderWithInvalidTimeoutSeconds() {
+    assertThatExceptionOfType(IllegalArgumentException.class)
+        .isThrownBy(() -> ExporterOpenTelemetryProperties.builder().timeoutSeconds(0))
+        .withMessage("0: Expecting timeoutSeconds > 0");
+
+    assertThatExceptionOfType(IllegalArgumentException.class)
+        .isThrownBy(() -> ExporterOpenTelemetryProperties.builder().timeoutSeconds(-1))
+        .withMessage("-1: Expecting timeoutSeconds > 0");
+  }
 }
diff --git a/prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/ExporterPropertiesTest.java b/prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/ExporterPropertiesTest.java
index f8dd74c13..6cde17648 100644
--- a/prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/ExporterPropertiesTest.java
+++ b/prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/ExporterPropertiesTest.java
@@ -56,5 +56,35 @@ void builder() {
             .build();
     assertThat(properties.getIncludeCreatedTimestamps()).isTrue();
     assertThat(properties.getExemplarsOnAllMetricTypes()).isTrue();
+    assertThat(properties.getPrometheusTimestampsInMs()).isFalse();
+  }
+
+  @Test
+  void defaultValues() {
+    ExporterProperties properties = ExporterProperties.builder().build();
+    assertThat(properties.getIncludeCreatedTimestamps()).isFalse();
+    assertThat(properties.getExemplarsOnAllMetricTypes()).isFalse();
+    assertThat(properties.getPrometheusTimestampsInMs()).isFalse();
+  }
+
+  @Test
+  void prometheusTimestampsInMs() {
+    ExporterProperties properties =
+        ExporterProperties.builder().prometheusTimestampsInMs(true).build();
+    assertThat(properties.getPrometheusTimestampsInMs()).isTrue();
+
+    properties =
+        load(new HashMap<>(Map.of("io.prometheus.exporter.prometheus_timestamps_in_ms", "true")));
+    assertThat(properties.getPrometheusTimestampsInMs()).isTrue();
+
+    assertThatExceptionOfType(PrometheusPropertiesException.class)
+        .isThrownBy(
+            () ->
+                load(
+                    new HashMap<>(
+                        Map.of("io.prometheus.exporter.prometheus_timestamps_in_ms", "invalid"))))
+        .withMessage(
+            "io.prometheus.exporter.prometheus_timestamps_in_ms: Expecting 'true' or 'false'. Found:"
+                + " invalid");
   }
 }
diff --git a/prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/ExporterPushgatewayPropertiesTest.java b/prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/ExporterPushgatewayPropertiesTest.java
index 147a2856e..c92e6f2f9 100644
--- a/prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/ExporterPushgatewayPropertiesTest.java
+++ b/prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/ExporterPushgatewayPropertiesTest.java
@@ -30,6 +30,50 @@ void load() {
                 + " Found: foo");
   }
 
+  @Test
+  void loadWithHttps() {
+    ExporterPushgatewayProperties properties =
+        load(Map.of("io.prometheus.exporter.pushgateway.scheme", "https"));
+    assertThat(properties.getScheme()).isEqualTo("https");
+  }
+
+  @Test
+  void loadWithEscapingSchemes() {
+    ExporterPushgatewayProperties properties =
+        load(Map.of("io.prometheus.exporter.pushgateway.escaping_scheme", "allow-utf-8"));
+    assertThat(properties.getEscapingScheme()).isEqualTo(EscapingScheme.ALLOW_UTF8);
+
+    properties = load(Map.of("io.prometheus.exporter.pushgateway.escaping_scheme", "values"));
+    assertThat(properties.getEscapingScheme()).isEqualTo(EscapingScheme.VALUE_ENCODING_ESCAPING);
+
+    properties = load(Map.of("io.prometheus.exporter.pushgateway.escaping_scheme", "underscores"));
+    assertThat(properties.getEscapingScheme()).isEqualTo(EscapingScheme.UNDERSCORE_ESCAPING);
+
+    properties = load(Map.of("io.prometheus.exporter.pushgateway.escaping_scheme", "dots"));
+    assertThat(properties.getEscapingScheme()).isEqualTo(EscapingScheme.DOTS_ESCAPING);
+  }
+
+  @Test
+  void loadWithInvalidEscapingScheme() {
+    assertThatExceptionOfType(PrometheusPropertiesException.class)
+        .isThrownBy(
+            () -> load(Map.of("io.prometheus.exporter.pushgateway.escaping_scheme", "invalid")))
+        .withMessage(
+            "io.prometheus.exporter.pushgateway.escaping_scheme: Illegal value. Expecting"
+                + " 'allow-utf-8', 'values', 'underscores', or 'dots'. Found: invalid");
+  }
+
+  @Test
+  void loadWithTimeouts() {
+    ExporterPushgatewayProperties properties =
+        load(
+            Map.of(
+                "io.prometheus.exporter.pushgateway.connect_timeout_seconds", "5",
+                "io.prometheus.exporter.pushgateway.read_timeout_seconds", "10"));
+    assertThat(properties.getConnectTimeout()).isEqualTo(Duration.ofSeconds(5));
+    assertThat(properties.getReadTimeout()).isEqualTo(Duration.ofSeconds(10));
+  }
+
   private static ExporterPushgatewayProperties load(Map<String, String> map) {
     Map<Object, Object> regularProperties = new HashMap<>(map);
     PropertySource propertySource = new PropertySource(regularProperties);
diff --git a/prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/PrometheusPropertiesTest.java b/prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/PrometheusPropertiesTest.java
index 7248a187d..3e891202a 100644
--- a/prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/PrometheusPropertiesTest.java
+++ b/prometheus-metrics-config/src/test/java/io/prometheus/metrics/config/PrometheusPropertiesTest.java
@@ -70,4 +70,62 @@ void testBuilder() {
     assertThat(result.getMetricProperties("unknown_metric")).isNull();
     assertThat(result.getExporterProperties()).isSameAs(defaults.getExporterProperties());
   }
+
+  @Test
+  void testMetricNameNormalization() {
+    PrometheusProperties.Builder builder = PrometheusProperties.builder();
+    MetricsProperties customProps =
+        MetricsProperties.builder().histogramClassicUpperBounds(0.1, 0.5).build();
+
+    // Test that metric names with dots are normalized to underscores
+    builder.putMetricProperty("my.metric.name", customProps);
+    PrometheusProperties result = builder.build();
+
+    // Should be able to retrieve with dots
+    assertThat(result.getMetricProperties("my.metric.name")).isSameAs(customProps);
+    // Should also be able to retrieve with underscores
+    assertThat(result.getMetricProperties("my_metric_name")).isSameAs(customProps);
+  }
+
+  @Test
+  void testMetricNameWithInvalidCharacters() {
+    PrometheusProperties.Builder builder = PrometheusProperties.builder();
+    MetricsProperties customProps =
+        MetricsProperties.builder().histogramClassicUpperBounds(0.1, 0.5).build();
+
+    // Test that invalid characters are converted to underscores
+    builder.putMetricProperty("metric-name@with#invalid$chars", customProps);
+    PrometheusProperties result = builder.build();
+
+    // Should normalize invalid characters to underscores
+    assertThat(result.getMetricProperties("metric-name@with#invalid$chars")).isSameAs(customProps);
+    assertThat(result.getMetricProperties("metric_name_with_invalid_chars")).isSameAs(customProps);
+  }
+
+  @Test
+  void testMetricNameWithValidCharacters() {
+    PrometheusProperties.Builder builder = PrometheusProperties.builder();
+    MetricsProperties customProps =
+        MetricsProperties.builder().histogramClassicUpperBounds(0.1, 0.5).build();
+
+    // Test valid characters: letters, numbers (not at start), underscore, colon
+    builder.putMetricProperty("my_metric:name123", customProps);
+    PrometheusProperties result = builder.build();
+
+    assertThat(result.getMetricProperties("my_metric:name123")).isSameAs(customProps);
+  }
+
+  @Test
+  void testMetricNameStartingWithNumber() {
+    PrometheusProperties.Builder builder = PrometheusProperties.builder();
+    MetricsProperties customProps =
+        MetricsProperties.builder().histogramClassicUpperBounds(0.1, 0.5).build();
+
+    // First digit is invalid (i=0), but subsequent digits are valid (i>0)
+    builder.putMetricProperty("123metric", customProps);
+    PrometheusProperties result = builder.build();
+
+    assertThat(result.getMetricProperties("123metric")).isSameAs(customProps);
+    assertThat(result.getMetricProperties("_23metric")).isSameAs(customProps);
+  }
 }
diff --git a/prometheus-metrics-exporter-httpserver/pom.xml b/prometheus-metrics-exporter-httpserver/pom.xml
index 07c2abd71..01fc2dab5 100644
--- a/prometheus-metrics-exporter-httpserver/pom.xml
+++ b/prometheus-metrics-exporter-httpserver/pom.xml
@@ -19,7 +19,7 @@
 
   <properties>
     <automatic.module.name>io.prometheus.metrics.exporter.httpserver</automatic.module.name>
-    <jacoco.line-coverage>0.45</jacoco.line-coverage>
+    <jacoco.line-coverage>0.60</jacoco.line-coverage>
   </properties>
 
   <dependencies>
diff --git a/prometheus-metrics-exporter-httpserver/src/test/java/io/prometheus/metrics/exporter/httpserver/HTTPServerTest.java b/prometheus-metrics-exporter-httpserver/src/test/java/io/prometheus/metrics/exporter/httpserver/HTTPServerTest.java
index 83c4a2874..ff2d55048 100644
--- a/prometheus-metrics-exporter-httpserver/src/test/java/io/prometheus/metrics/exporter/httpserver/HTTPServerTest.java
+++ b/prometheus-metrics-exporter-httpserver/src/test/java/io/prometheus/metrics/exporter/httpserver/HTTPServerTest.java
@@ -85,6 +85,29 @@ public Result authenticate(HttpExchange exchange) {
     run(server, "/", 204, "");
   }
 
+  @Test
+  void testSubjectDoAsWithInvalidSubject() throws Exception {
+    Authenticator authenticator =
+        new Authenticator() {
+          @Override
+          public Result authenticate(HttpExchange exchange) {
+            exchange.setAttribute("aa", "not-a-subject");
+            return new Success(new HttpPrincipal("user", "/"));
+          }
+        };
+
+    HttpHandler handler = exchange -> exchange.sendResponseHeaders(204, -1);
+    HTTPServer server =
+        HTTPServer.builder()
+            .port(0)
+            .authenticator(authenticator)
+            .defaultHandler(handler)
+            .authenticatedSubjectAttributeName("aa")
+            .buildAndStart();
+
+    run(server, "/", 403, "");
+  }
+
   @Test
   void defaultHandler() throws Exception {
     run(
diff --git a/prometheus-metrics-exporter-httpserver/src/test/java/io/prometheus/metrics/exporter/httpserver/HttpExchangeAdapterTest.java b/prometheus-metrics-exporter-httpserver/src/test/java/io/prometheus/metrics/exporter/httpserver/HttpExchangeAdapterTest.java
new file mode 100644
index 000000000..19bc0d66e
--- /dev/null
+++ b/prometheus-metrics-exporter-httpserver/src/test/java/io/prometheus/metrics/exporter/httpserver/HttpExchangeAdapterTest.java
@@ -0,0 +1,49 @@
+package io.prometheus.metrics.exporter.httpserver;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import com.sun.net.httpserver.Headers;
+import com.sun.net.httpserver.HttpExchange;
+import java.net.URI;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+class HttpExchangeAdapterTest {
+
+  @Test
+  void getRequestPath() {
+    HttpExchange httpExchange = mock(HttpExchange.class);
+    when(httpExchange.getRequestURI()).thenReturn(URI.create("/metrics?name=test"));
+    HttpExchangeAdapter adapter = new HttpExchangeAdapter(httpExchange);
+    assertThat(adapter.getRequest().getRequestPath()).isEqualTo("/metrics");
+  }
+
+  @Test
+  void getRequestPathWithoutQueryString() {
+    HttpExchange httpExchange = mock(HttpExchange.class);
+    when(httpExchange.getRequestURI()).thenReturn(URI.create("/metrics"));
+    HttpExchangeAdapter adapter = new HttpExchangeAdapter(httpExchange);
+    assertThat(adapter.getRequest().getRequestPath()).isEqualTo("/metrics");
+  }
+
+  @Test
+  void getHeadersWhenPresent() {
+    HttpExchange httpExchange = mock(HttpExchange.class);
+    Headers headers = new Headers();
+    headers.put("Accept", List.of("text/plain"));
+    when(httpExchange.getRequestHeaders()).thenReturn(headers);
+    HttpExchangeAdapter adapter = new HttpExchangeAdapter(httpExchange);
+    assertThat(adapter.getRequest().getHeaders("Accept").nextElement()).isEqualTo("text/plain");
+  }
+
+  @Test
+  void getHeadersWhenNotPresent() {
+    HttpExchange httpExchange = mock(HttpExchange.class);
+    Headers headers = new Headers();
+    when(httpExchange.getRequestHeaders()).thenReturn(headers);
+    HttpExchangeAdapter adapter = new HttpExchangeAdapter(httpExchange);
+    assertThat(adapter.getRequest().getHeaders("Accept").hasMoreElements()).isFalse();
+  }
+}
diff --git a/prometheus-metrics-exporter-opentelemetry/src/test/java/io/prometheus/metrics/exporter/opentelemetry/otelmodel/ExponentialHistogramPointDataImplTest.java b/prometheus-metrics-exporter-opentelemetry/src/test/java/io/prometheus/metrics/exporter/opentelemetry/otelmodel/ExponentialHistogramPointDataImplTest.java
new file mode 100644
index 000000000..066913420
--- /dev/null
+++ b/prometheus-metrics-exporter-opentelemetry/src/test/java/io/prometheus/metrics/exporter/opentelemetry/otelmodel/ExponentialHistogramPointDataImplTest.java
@@ -0,0 +1,92 @@
+package io.prometheus.metrics.exporter.opentelemetry.otelmodel;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.sdk.metrics.data.ExponentialHistogramBuckets;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+class ExponentialHistogramPointDataImplTest {
+
+  private static final ExponentialHistogramBuckets EMPTY_BUCKETS =
+      ExponentialHistogramBuckets.create(0, 0, List.of());
+
+  @Test
+  void hasMinReturnsTrueWhenMinIsNotNaN() {
+    ExponentialHistogramPointDataImpl histogramPoint =
+        new ExponentialHistogramPointDataImpl(
+            0,
+            10.0,
+            5,
+            0,
+            1.0,
+            5.0,
+            EMPTY_BUCKETS,
+            EMPTY_BUCKETS,
+            0L,
+            1L,
+            Attributes.empty(),
+            List.of());
+    assertThat(histogramPoint.hasMin()).isTrue();
+    assertThat(histogramPoint.getMin()).isEqualTo(1.0);
+  }
+
+  @Test
+  void hasMinReturnsFalseWhenMinIsNaN() {
+    ExponentialHistogramPointDataImpl histogramPoint =
+        new ExponentialHistogramPointDataImpl(
+            0,
+            10.0,
+            5,
+            0,
+            Double.NaN,
+            5.0,
+            EMPTY_BUCKETS,
+            EMPTY_BUCKETS,
+            0L,
+            1L,
+            Attributes.empty(),
+            List.of());
+    assertThat(histogramPoint.hasMin()).isFalse();
+  }
+
+  @Test
+  void hasMaxReturnsTrueWhenMaxIsNotNaN() {
+    ExponentialHistogramPointDataImpl histogramPoint =
+        new ExponentialHistogramPointDataImpl(
+            0,
+            10.0,
+            5,
+            0,
+            1.0,
+            5.0,
+            EMPTY_BUCKETS,
+            EMPTY_BUCKETS,
+            0L,
+            1L,
+            Attributes.empty(),
+            List.of());
+    assertThat(histogramPoint.hasMax()).isTrue();
+    assertThat(histogramPoint.getMax()).isEqualTo(5.0);
+  }
+
+  @Test
+  void hasMaxReturnsFalseWhenMaxIsNaN() {
+    ExponentialHistogramPointDataImpl histogramPoint =
+        new ExponentialHistogramPointDataImpl(
+            0,
+            10.0,
+            5,
+            0,
+            1.0,
+            Double.NaN,
+            EMPTY_BUCKETS,
+            EMPTY_BUCKETS,
+            0L,
+            1L,
+            Attributes.empty(),
+            List.of());
+    assertThat(histogramPoint.hasMax()).isFalse();
+  }
+}
diff --git a/prometheus-metrics-exporter-opentelemetry/src/test/java/io/prometheus/metrics/exporter/opentelemetry/otelmodel/HistogramPointDataImplTest.java b/prometheus-metrics-exporter-opentelemetry/src/test/java/io/prometheus/metrics/exporter/opentelemetry/otelmodel/HistogramPointDataImplTest.java
new file mode 100644
index 000000000..b5c4e9373
--- /dev/null
+++ b/prometheus-metrics-exporter-opentelemetry/src/test/java/io/prometheus/metrics/exporter/opentelemetry/otelmodel/HistogramPointDataImplTest.java
@@ -0,0 +1,80 @@
+package io.prometheus.metrics.exporter.opentelemetry.otelmodel;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import io.opentelemetry.api.common.Attributes;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+class HistogramPointDataImplTest {
+
+  @Test
+  void hasMinReturnsTrueWhenMinIsNotNaN() {
+    HistogramPointDataImpl histogramPoint =
+        new HistogramPointDataImpl(
+            10.0,
+            5,
+            1.0,
+            5.0,
+            List.of(1.0, 2.0),
+            List.of(2L, 3L),
+            0L,
+            1L,
+            Attributes.empty(),
+            List.of());
+    assertThat(histogramPoint.hasMin()).isTrue();
+    assertThat(histogramPoint.getMin()).isEqualTo(1.0);
+  }
+
+  @Test
+  void hasMinReturnsFalseWhenMinIsNaN() {
+    HistogramPointDataImpl histogramPoint =
+        new HistogramPointDataImpl(
+            10.0,
+            5,
+            Double.NaN,
+            5.0,
+            List.of(1.0, 2.0),
+            List.of(2L, 3L),
+            0L,
+            1L,
+            Attributes.empty(),
+            List.of());
+    assertThat(histogramPoint.hasMin()).isFalse();
+  }
+
+  @Test
+  void hasMaxReturnsTrueWhenMaxIsNotNaN() {
+    HistogramPointDataImpl histogramPoint =
+        new HistogramPointDataImpl(
+            10.0,
+            5,
+            1.0,
+            5.0,
+            List.of(1.0, 2.0),
+            List.of(2L, 3L),
+            0L,
+            1L,
+            Attributes.empty(),
+            List.of());
+    assertThat(histogramPoint.hasMax()).isTrue();
+    assertThat(histogramPoint.getMax()).isEqualTo(5.0);
+  }
+
+  @Test
+  void hasMaxReturnsFalseWhenMaxIsNaN() {
+    HistogramPointDataImpl histogramPoint =
+        new HistogramPointDataImpl(
+            10.0,
+            5,
+            1.0,
+            Double.NaN,
+            List.of(1.0, 2.0),
+            List.of(2L, 3L),
+            0L,
+            1L,
+            Attributes.empty(),
+            List.of());
+    assertThat(histogramPoint.hasMax()).isFalse();
+  }
+}
diff --git a/prometheus-metrics-exporter-pushgateway/src/test/java/io/prometheus/metrics/exporter/pushgateway/SchemeTest.java b/prometheus-metrics-exporter-pushgateway/src/test/java/io/prometheus/metrics/exporter/pushgateway/SchemeTest.java
index 6695a2911..0f6bf61d9 100644
--- a/prometheus-metrics-exporter-pushgateway/src/test/java/io/prometheus/metrics/exporter/pushgateway/SchemeTest.java
+++ b/prometheus-metrics-exporter-pushgateway/src/test/java/io/prometheus/metrics/exporter/pushgateway/SchemeTest.java
@@ -9,6 +9,8 @@ class SchemeTest {
 
   @Test
   void fromString() {
+    assertThat(Scheme.fromString("http")).isEqualTo(Scheme.HTTP);
+    assertThat(Scheme.fromString("https")).isEqualTo(Scheme.HTTPS);
     assertThat(Scheme.HTTP).hasToString("http");
     assertThat(Scheme.HTTPS).hasToString("https");
     assertThatExceptionOfType(IllegalArgumentException.class)
diff --git a/prometheus-metrics-exposition-textformats/pom.xml b/prometheus-metrics-exposition-textformats/pom.xml
index 1aeba0707..1f34a5dde 100644
--- a/prometheus-metrics-exposition-textformats/pom.xml
+++ b/prometheus-metrics-exposition-textformats/pom.xml
@@ -19,7 +19,7 @@
 
   <properties>
     <automatic.module.name>io.prometheus.writer.text</automatic.module.name>
-    <jacoco.line-coverage>0.50</jacoco.line-coverage>
+    <jacoco.line-coverage>0.60</jacoco.line-coverage>
   </properties>
 
   <dependencies>
diff --git a/prometheus-metrics-exposition-textformats/src/test/java/io/prometheus/metrics/expositionformats/PrometheusProtobufWriterTest.java b/prometheus-metrics-exposition-textformats/src/test/java/io/prometheus/metrics/expositionformats/PrometheusProtobufWriterTest.java
index 26561bf46..59b413d81 100644
--- a/prometheus-metrics-exposition-textformats/src/test/java/io/prometheus/metrics/expositionformats/PrometheusProtobufWriterTest.java
+++ b/prometheus-metrics-exposition-textformats/src/test/java/io/prometheus/metrics/expositionformats/PrometheusProtobufWriterTest.java
@@ -13,6 +13,13 @@ class PrometheusProtobufWriterTest {
   @Test
   void accepts() {
     assertThat(writer.accepts(null)).isFalse();
+    assertThat(writer.accepts("text/plain")).isFalse();
+    assertThat(writer.accepts("application/vnd.google.protobuf")).isFalse();
+    assertThat(writer.accepts("proto=io.prometheus.client.MetricFamily")).isFalse();
+    assertThat(
+            writer.accepts(
+                "application/vnd.google.protobuf; proto=io.prometheus.client.MetricFamily"))
+        .isTrue();
   }
 
   @Test
@@ -34,4 +41,9 @@ void toDebugString() {
     assertThatCode(() -> writer.toDebugString(null, EscapingScheme.ALLOW_UTF8))
         .isInstanceOf(UnsupportedOperationException.class);
   }
+
+  @Test
+  void isAvailable() {
+    assertThat(writer.isAvailable()).isFalse();
+  }
 }
diff --git a/prometheus-metrics-instrumentation-dropwizard5/pom.xml b/prometheus-metrics-instrumentation-dropwizard5/pom.xml
index 4fc7524f4..14704695b 100644
--- a/prometheus-metrics-instrumentation-dropwizard5/pom.xml
+++ b/prometheus-metrics-instrumentation-dropwizard5/pom.xml
@@ -19,7 +19,7 @@
 
   <properties>
     <automatic.module.name>io.prometheus.metrics.instrumentation.dropwizard5</automatic.module.name>
-    <jacoco.line-coverage>0.50</jacoco.line-coverage>
+    <jacoco.line-coverage>0.60</jacoco.line-coverage>
   </properties>
 
   <dependencies>
diff --git a/prometheus-metrics-instrumentation-jvm/pom.xml b/prometheus-metrics-instrumentation-jvm/pom.xml
index e7b379207..2aaf675ad 100644
--- a/prometheus-metrics-instrumentation-jvm/pom.xml
+++ b/prometheus-metrics-instrumentation-jvm/pom.xml
@@ -19,7 +19,7 @@
 
   <properties>
     <automatic.module.name>io.prometheus.metrics.instrumentation.jvm</automatic.module.name>
-    <jacoco.line-coverage>0.55</jacoco.line-coverage>
+    <jacoco.line-coverage>0.60</jacoco.line-coverage>
   </properties>
 
   <dependencies>
diff --git a/prometheus-metrics-instrumentation-jvm/src/test/java/io/prometheus/metrics/instrumentation/jvm/JvmMemoryPoolAllocationMetricsTest.java b/prometheus-metrics-instrumentation-jvm/src/test/java/io/prometheus/metrics/instrumentation/jvm/JvmMemoryPoolAllocationMetricsTest.java
index 3a8138baf..2f681ce89 100644
--- a/prometheus-metrics-instrumentation-jvm/src/test/java/io/prometheus/metrics/instrumentation/jvm/JvmMemoryPoolAllocationMetricsTest.java
+++ b/prometheus-metrics-instrumentation-jvm/src/test/java/io/prometheus/metrics/instrumentation/jvm/JvmMemoryPoolAllocationMetricsTest.java
@@ -47,6 +47,10 @@ void testListenerLogic() {
     // Decrease to 17, then increase by 3
     listener.handleMemoryPool("TestPool", 17, 20);
     assertThat(getCountByPool("test", "TestPool", registry.scrape())).isEqualTo(153);
+
+    // Edge case: before < last (tests diff1 < 0 branch)
+    listener.handleMemoryPool("TestPool", 10, 15);
+    assertThat(getCountByPool("test", "TestPool", registry.scrape())).isEqualTo(158);
   }
 
   private double getCountByPool(String metricName, String poolName, MetricSnapshots snapshots) {
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/Collector.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/Collector.java
index dbd7c36f5..beca6001e 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/Collector.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/Collector.java
@@ -67,8 +67,8 @@ default MetricSnapshot collect(
    *       and the metric name is excluded.
    * </ol>
    *
-   * Returning {@code null} means checks are omitted (registration the metric always succeeds), and
-   * the collector is always scraped (the result is dropped after scraping if a name filter is
+   * <p>Returning {@code null} means checks are omitted (registration the metric always succeeds),
+   * and the collector is always scraped (the result is dropped after scraping if a name filter is
    * present and the metric name is excluded).
    *
    * <p>If your metric has a name that does not change at runtime it is a good idea to overwrite
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/MultiCollector.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/MultiCollector.java
index e4a224bdf..27ac3e10c 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/MultiCollector.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/registry/MultiCollector.java
@@ -62,9 +62,9 @@ default MetricSnapshots collect(
    *       and all names are excluded.
    * </ol>
    *
-   * Returning an empty list means checks are omitted (registration metric always succeeds), and the
-   * collector is always scraped (if a name filter is present and all names are excluded the result
-   * is dropped).
+   * <p>Returning an empty list means checks are omitted (registration metric always succeeds), and
+   * the collector is always scraped (if a name filter is present and all names are excluded the
+   * result is dropped).
    *
    * <p>If your collector returns a constant list of metrics that have names that do not change at
    * runtime it is a good idea to overwrite this and return the names.
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/PrometheusNaming.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/PrometheusNaming.java
index 71de5d0b4..4f766fdad 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/PrometheusNaming.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/PrometheusNaming.java
@@ -27,7 +27,7 @@ public class PrometheusNaming {
    *   <li>OpenTelemetry: {@code process_runtime_jvm_buffer_count}
    * </ul>
    *
-   * We do not treat {@code _count} and {@code _sum} as reserved suffixes here for compatibility
+   * <p>We do not treat {@code _count} and {@code _sum} as reserved suffixes here for compatibility
    * with these libraries. However, there is a risk of name conflict if someone creates a gauge
    * named {@code my_data_count} and a histogram or summary named {@code my_data}, because the
    * histogram or summary will implicitly have a sample named {@code my_data_count}.
@@ -47,9 +47,9 @@ public class PrometheusNaming {
    *   <li>The name MUST NOT end with one of the {@link #RESERVED_METRIC_NAME_SUFFIXES}.
    * </ul>
    *
-   * If a metric has a {@link Unit}, the metric name SHOULD end with the unit as a suffix. Note that
-   * <a href="https://openmetrics.io/">OpenMetrics</a> requires metric names to have their unit as
-   * suffix, and we implement this in {@code prometheus-metrics-core}. However, {@code
+   * <p>If a metric has a {@link Unit}, the metric name SHOULD end with the unit as a suffix. Note
+   * that <a href="https://openmetrics.io/">OpenMetrics</a> requires metric names to have their unit
+   * as suffix, and we implement this in {@code prometheus-metrics-core}. However, {@code
    * prometheus-metrics-model} does not enforce Unit suffixes.
    *
    * <p>Example: If you create a Counter for a processing time with Unit {@link Unit#SECONDS
diff --git a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/Unit.java b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/Unit.java
index 31a9524e7..6e652af13 100644
--- a/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/Unit.java
+++ b/prometheus-metrics-model/src/main/java/io/prometheus/metrics/model/snapshots/Unit.java
@@ -9,8 +9,8 @@
  *     new Unit("myUnit");
  * </pre>
  *
- * Note that in Prometheus, units are largely based on SI base units (seconds, bytes, joules, grams,
- * meters, ratio, volts, amperes, and Celsius).
+ * <p>Note that in Prometheus, units are largely based on SI base units (seconds, bytes, joules,
+ * grams, meters, ratio, volts, amperes, and Celsius).
  */
 public final class Unit {