Python: More review suggestions

Author: yoff

python/change-notes/2021-03-12-small-api-enhancements.md

@@ -1,5 +1,4 @@
 lgtm,codescanning
-* Make `ParameterNode` extend `LocalSourceNode`, thus making members like `flowsTo` available.
-* Add member predicate `taintFlowsTo` to `LocalSourceNode` facilitating smoother syntax for local taint tracking.
-* Add member `getALocalTaintSource` to `DataFlow::Node` facilitating smoother syntax for local taint tracking.
-* Add predicate `parameterNode` to map from a `Parameter` to a data-flow node.
+* The class ParameterNode now extends LocalSourceNode, thus making methods like flowsTo available.
+* Local taint tracking can now be performed using the `taintFlowsTo` method on the `LocalSourceNode` class. Conversely, the new member predicate `getALocalTaintSource` can be called on a `DataFlow::Node` to obtain a `LocalSourceNode` from which taint can be tracked locally to that data-flow node.
+* The new predicate `parameterNode` can now be used to map from a `Parameter` to a data-flow node.

python/ql/src/semmle/python/dataflow/new/internal/DataFlowPublic.qll

@@ -136,7 +136,7 @@ class Node extends TNode {
   LocalSourceNode backtrack(TypeBackTracker t2, TypeBackTracker t) { t2 = t.step(result, this) }
 
   /**
-   * Gets a local source node from which data may flow to this node in zero or more local steps.
+   * Gets a local source node from which data may flow to this node in zero or more local data-flow steps.
    */
   LocalSourceNode getALocalSource() { result.flowsTo(this) }