def check_xsrf_cookie(self):
        token = (self.get_argument("_xsrf", None) or
                 self.request.headers.get("X-Xsrftoken") or
                 self.request.headers.get("X-Csrftoken"))
        if not token:
            raise HTTPError(403, "'_xsrf' argument missing from POST")
        _, token, _ = self._decode_xsrf_token(token)
        _, expected_token, _ = self._get_raw_xsrf_token()
        if not _time_independent_equals(utf8(token), utf8(expected_token)):
            raise HTTPError(403, "XSRF cookie does not match POST argument")
Verifies that the ``_xsrf`` cookie matches the ``_xsrf`` argument.
dataset/ETHPy150Open RobotWebTools/rosbridge_suite/rosbridge_server/src/tornado/web.py/RequestHandler.check_xsrf_cookie