@Override
  public GrParameter addParameter(GrParameter parameter) {
    GrParameterList parameterList = getParameterList();
    if (getArrow() == null) {
      final GrParameterList newParamList = (GrParameterList)addAfter(parameterList, getLBrace());
      parameterList.delete();
      ASTNode next = newParamList.getNode().getTreeNext();
      getNode().addLeaf(GroovyTokenTypes.mCLOSABLE_BLOCK_OP, "->", next);
      return (GrParameter)newParamList.add(parameter);
    }

    return (GrParameter)parameterList.add(parameter);
  }
@Override
  public GrParameter addParameter(GrParameter parameter)