code: private int endCheckLabel()
      {
          int rv = END_UNREACHED;
  
          rv = next.endCheck();
          rv |= getIntProp(CONTROL_BLOCK_PROP, END_UNREACHED);
  
          return rv;
      }
docs: A labelled statement implies that there maybe a break to the label. The
  function processes the labelled statement and then checks the
  CONTROL_BLOCK_PROP property to see if there is ever a break to the
  particular label.
  @return logical OR of END_* flags