code: @Override
      public void visitCode(Code obj) {
          collectionGroups.clear();
          groupToIterator.clear();
          loops.clear();
          buildVariableEndScopeMap();
  
          super.visitCode(obj);
      }
docs: implements the visitor to reset the stack, collectionGroups, groupToIterator and loops
  
  @param obj
  the context object of the currently parsed code block