trying fix build

Author: maxkvant

006-Xunit/src/main/java/task/Tester/Tester.java

@@ -1,7 +1,7 @@
 package task.Tester;
 
 import com.google.common.collect.ImmutableList;
-import com.sun.istack.internal.NotNull;
+import org.jetbrains.annotations.NotNull;
 import task.annotations.*;
 
 import java.lang.annotation.Annotation;

006-Xunit/src/main/java/task/annotations/Checks.java

@@ -1,7 +1,9 @@
 package task.annotations;
 
+import org.jetbrains.annotations.NotNull;
+
 public class Checks {
-    final static String nullString = "";
+    final static @NotNull String nullString = "";
     final class MyThrowable extends Throwable {}
 
     public static boolean hasException(Test test) {