Different Node classes in the same package #122

import importlib
import bblfsh

m = importlib.import_module('bblfsh.gopkg.in.bblfsh.sdk.v1.protocol.generated_pb2_grpc')
print(id(m.generated__pb2.gopkg_dot_in_dot_bblfsh_dot_sdk_dot_v1_dot_uast_dot_generated__pb2.Node))
print(id(bblfsh.Node))
m = importlib.import_module('bblfsh.gopkg.in.bblfsh.sdk.v1.uast.generated_pb2')
print(id(m.Node))

The first printed number is different from the rest. That's because bblfsh/gopkg/in/bblfsh/sdk/v1/protocol/generated_pb2_grpc.py does

import generated_pb2 as generated__pb2

As soon as the module is imported from the different PYTHONPATH, the classes get screwed and although they are really the same, they are different. Hence isinstance() returns False on 3.7, etc.

Suggested fix: remove all the tricks with PYTHONPATH and make all the imports absolute everywhere and starting with bblfsh..