code: @Override
      public void visitLabel(Label label) {
          super.visitLabel(label);
  
          if (waitingForSuper) {
              // Get what should be the shape of the stack in the handler.
              // Not all labels are branch targets so only deal with targets
              if (branchTargets.containsKey(label)) {
                  currentStack = branchTargets.get(label);
              }
          } else {
              pendingExceptionHandlerTypeName = handlers.get(label);
          }
      }
docs: Visit a label. We will use this to determine when we've reached an
  exception handler block.
  
  @param label
  the label to visit