Java: Address review comments.

java/ql/src/utils/modelgenerator/internal/CaptureSummaryFlowQuery.qll

@@ -73,8 +73,9 @@ string captureFlow(DataFlowTargetApi api) {
 }
 
 /**
- * Gets the neutral summary for `api`, if any.
- * A neutral model is generated, if there does not exist any summary model.
+ * Gets the neutral summary model for `api`, if any.
+ * A neutral summary model is generated, if we are not generating
+ * a summary model that applies to `api`.
  */
 string captureNoFlow(DataFlowTargetApi api) {
   not exists(DataFlowTargetApi api0 | exists(captureFlow(api0)) and api0.lift() = api.lift()) and

java/ql/test/utils/modelgenerator/dataflow/p/MultipleImpl2.java

@@ -2,6 +2,9 @@ package p;
 
 class MultipleImpl2 {
 
+    // Multiple implementations of the same interface.
+    // This is used to test that we only generate a summary model and
+    // not neutral summary model for `IInterface.m`.
     public interface IInterface {
         Object m(Object value);
     }