'Send a HTTP POST request using keystone auth
:param str url: the relative url to send the post request to
:param dict body: the request body
:param dict headers: The headers to use for the request
:param bool extra_headers: Boolean value than indicates if the headers
returned by the get_headers() method are to
be used but additional headers are needed in
the request pass them in as a dict.
:param bool chunked: sends the body with chunked encoding
:return: a tuple with the first entry containing the response headers
and the second the response body
:rtype: tuple'

def post(self, url, body, headers=None, extra_headers=False, chunked=False):

    return self.request('POST', url, extra_headers, headers, body, chunked)
