Send batch request to Postmark API.
        Returns result of :func:`requests.post`.

        :param messages: Batch messages to send to the Postmark API.
        :type messages: A list of :class:`Message`
        :param api_key: Your Postmark API key. Defaults to `self.api_key`.
        :param test: Make a test request to the Postmark API.
            Defaults to `self.test`.
        :param secure: Use the https Postmark API. Defaults to `self.secure`.
        :param \*\*request_args: Passed to :func:`requests.request`
        :rtype: :class:`BatchSendResponse`

def send(self, messages=None, api_key=None, secure=None, test=None,
             **request_args):
        '''Send batch request to Postmark API.
        Returns result of :func:`requests.post`.

        :param messages: Batch messages to send to the Postmark API.
        :type messages: A list of :class:`Message`
        :param api_key: Your Postmark API key. Defaults to `self.api_key`.
        :param test: Make a test request to the Postmark API.
            Defaults to `self.test`.
        :param secure: Use the https Postmark API. Defaults to `self.secure`.
        :param \*\*request_args: Passed to :func:`requests.request`
        :rtype: :class:`BatchSendResponse`
        '''
        return super(BatchSender, self).send(message=messages, test=test,
                                             api_key=api_key, secure=secure,
                                             **request_args)