A thread local instance of httplib2.Http.

        Returns:
            httplib2.Http: An Http instance authorized by the credentials.

def http(self):
        """A thread local instance of httplib2.Http.

        Returns:
            httplib2.Http: An Http instance authorized by the credentials.
        """
        if self._use_cached_http and hasattr(self._local, 'http'):
            return self._local.http
        if self._http_replay is not None:
            # httplib2 instance is not thread safe
            http = self._http_replay
        else:
            http = _build_http()
        authorized_http = google_auth_httplib2.AuthorizedHttp(
            self._credentials, http=http)
        if self._use_cached_http:
            self._local.http = authorized_http
        return authorized_http