Overhead in `put()` due to debugging info

While profiling our NDB app, I noticed protobuf `__repr__` calls appearing higher than expected in our total profile. According to the profile, These are called from within `put()` in `_datastore_api.py`.

As far as I can tell, the culprit seems to be [this line](https://github.com/googleapis/python-ndb/blob/85943208a884e9c232693e87339e701d27c78d37/google/cloud/ndb/_datastore_api.py#L505), which serializes a text representation of the entire RPC `put` command into the `info` field. Could it be that this creates unnecessary overhead for large entities?