PMD rule AbstractClassWithoutAbstractMethod is activated. Issue #744

config/pmd.xml

@@ -115,7 +115,6 @@
     <exclude name="ImmutableField"/>
     <!-- this rule does not have any option, unreasonable to use -->
     <exclude name="MissingBreakInSwitch"/>
-    <exclude name="AbstractClassWithoutAbstractMethod"/>
     <exclude name="SimplifyConditional"/>
     <exclude name="CompareObjectsWithEquals"/>
     <exclude name="PositionLiteralsFirstInComparisons"/>

src/main/java/com/puppycrawl/tools/checkstyle/checks/DeclarationCollector.java

@@ -229,7 +229,7 @@ public abstract class DeclarationCollector extends Check
      * @author Stephen Bloch
      * June 19, 2003
      */
-    private abstract static class LexicalFrame
+    private static class LexicalFrame
     {
         /** Set of name of variables declared in this frame. */
         private final Set<String> varNames;