code: @Override
      public void visitCode(final Code obj) {
          try {
              localCollections = new HashMap<>();
              localScopeEnds = new HashMap<>();
              localSourceLineAnnotations = new HashMap<>();
              stack.resetForMethodEntry(this);
              super.visitCode(obj);
          } finally {
              localCollections = null;
              localScopeEnds = null;
              localSourceLineAnnotations = null;
          }
      }
docs: implements the visitor to reset the opcode stack, and clear the various collections
  
  @param obj
  the currently parsed code block