In case of submitting many contents (such as the whole /travel page includes dependences), an error will be thrown as below. This is known issue as number of submitted segments is over google's threshold.

you can send up to 128 segments. There are also limitations on the number of overall characters, but that is well documented on failure.

Request payload size exceeds the limit: 204800 bytes.

I have requested that the error for too many segments informs you of how many segments are allowed.

https://github.com/googleapis/google-cloud-python/issues/5425