code: private function parseInputFieldsDefinition()
      {
          return $this->peek(Token::BRACE_L)
              ? $this->many(
                  Token::BRACE_L,
                  function () {
                      return $this->parseInputValueDef();
                  },
                  Token::BRACE_R
              )
              : new NodeList([]);
      }
docs: @return InputValueDefinitionNode[]|NodeList
  
  @throws SyntaxError