https://grpc.io/docs/languages/python/quickstart/
https://grpc.io/docs/what-is-grpc/introduction/
https://grpc.io/docs/languages/python/basics/
https://github.com/grpc/grpc/tree/v1.38.0/examples/python/route_guide
https://developers.google.com/protocol-buffers/docs/reference/python-generated