Sends the request out for transmission.

        Args:
            http_verb (str): The HTTP verb. e.g. 'GET' or 'POST'.
            api_url (str): The Slack API url. e.g. 'https://slack.com/api/chat.postMessage'
            req_args (dict): The request arguments to be attached to the request.
            e.g.
            {
                json: {
                    'attachments': [{"pretext": "pre-hello", "text": "text-world"}],
                    'channel': '#random'
                }
            }
        Returns:
            The response parsed into a SlackResponse object.

async def _send(self, http_verb, api_url, req_args):
        """Sends the request out for transmission.

        Args:
            http_verb (str): The HTTP verb. e.g. 'GET' or 'POST'.
            api_url (str): The Slack API url. e.g. 'https://slack.com/api/chat.postMessage'
            req_args (dict): The request arguments to be attached to the request.
            e.g.
            {
                json: {
                    'attachments': [{"pretext": "pre-hello", "text": "text-world"}],
                    'channel': '#random'
                }
            }
        Returns:
            The response parsed into a SlackResponse object.
        """
        res = await self._request(
            http_verb=http_verb, api_url=api_url, req_args=req_args
        )
        data = {
            "client": self,
            "http_verb": http_verb,
            "api_url": api_url,
            "req_args": req_args,
        }
        return SlackResponse(**{**data, **res}).validate()