将docstring返回.

        system.methodHelp('add') => "Adds two integers together"

        Return:
            (str): - 函数的帮助文本

def system_methodHelp(self, method_name: str)->str:
        """将docstring返回.

        system.methodHelp('add') => "Adds two integers together"

        Return:
            (str): - 函数的帮助文本

        """
        method = None
        if method_name in self.funcs:
            method = self.funcs[method_name]
        elif self.instance is not None:
            try:
                method = resolve_dotted_attribute(
                    self.instance,
                    method_name,
                    self.allow_dotted_names
                )
            except AttributeError:
                pass
        if method is None:
            return ""
        else:
            return pydoc.getdoc(method)