def METHOD_NAME(self, channel, client_thread):
    handler = GrpcHandler(channel=channel)
    channel.close()
    # Retry is unable to test
    has_collection_future = client_thread.submit(
        handler.has_collection, "fake", timeout=0)
    (invocation_metadata, request, rpc) = (
        channel.take_unary_unary(descriptor.methods_by_name['DescribeCollection']))
    rpc.send_initial_metadata(())
    expected_result = milvus_pb2.DescribeCollectionResponse()
    rpc.terminate(expected_result, (), grpc.StatusCode.UNAVAILABLE, 'server Unavailable')
    with pytest.raises(MilvusException):
        has_collection_future.result()