def __call__(self, request):
<EOL>if pendulum.now() + self._token_expiration_buffer >= self._token_expiration:<EOL><INDENT>self.authenticate()<EOL><DEDENT>request.headers.update(self._login_headers)<EOL>return request<EOL>
Attach necessary headers to all requests

        Automatically reauthenticate before sending request when nearing token expiration