code: def setUp(self):
      super().setUp()
      self.stub = _create_mock_client()
      addr = "localhost:0"  # invalid, just in case it tries to connect
      self.provider = grpc_provider.GrpcDataProvider(addr, self.stub)
      self.ctx = context.RequestContext()
  
imports: from unittest import mock
  import grpc
  import grpc_testing
  import numpy
  from tensorboard import errors
  from tensorboard import test
  from tensorboard import context
  from tensorboard.data import grpc_provider
  from tensorboard.data import provider
  from tensorboard.data.proto import data_provider_pb2
  from tensorboard.data.proto import data_provider_pb2_grpc
  from tensorboard.util import tensor_util
label_desc: Use image node_id 1 for calling the GrpcDataProviderTest obj's underlying member method code with example usage: obj.setUp() without return types