This new behavior causes an error: run_query() got an unexpected keyword argument 'request' because when the GOOGLE_CLOUD_DISABLE_GRPC environment variable is set (which is a requirement in some runtimes, e.g., when using gunicorn with gevent), the underlying HTTPDatastoreAPI#run_query method does not accept a request parameter.

Example:

# run_query.py

from google.cloud import datastore

client = datastore.Client()  # Assuming an auth'd environment
results = [entity for entity in client.query(kind="Foo").fetch()]

I feel like this can be fixed by updating the signature for the HTTPDatastoreAPI#run_query to accept request and only subsequently build the request object if it's not passed in, so that the signatures match for all implementations.