def upload_file(self, api_token, file_path, **kwargs):
        """Upload a file suitable to be passed as a file_attachment.

        :param api_token: The user's login api_token.
        :type api_token: str
        :param file_path: The path of the file to be uploaded.
        :type file_path: str
        :return: The HTTP response to the request.
        :rtype: :class:`requests.Response`
        """
        params = {
            'token': api_token,
            'file_name': os.path.basename(file_path)
        }
        with open(file_path, 'rb') as f:
            files = {'file': f}
            return self._post('upload_file', params, files, **kwargs)
Upload a file suitable to be passed as a file_attachment.

        :param api_token: The user's login api_token.
        :type api_token: str
        :param file_path: The path of the file to be uploaded.
        :type file_path: str
        :return: The HTTP response to the request.
        :rtype: :class:`requests.Response`