@Override
    public PsiType fun(GrMethodCall methodCall, PsiMethod method) {
      GrArgumentList argumentList = methodCall.getArgumentList();
      GrExpression[] arguments = argumentList.getExpressionArguments();
      if (arguments.length == 0) return null;

      return arguments[0].getType();
    }
@Override
    public PsiType fun(GrMethodCall methodCall, PsiMethod method)