t.Run("sum_error", func(t *testing.T) {
		stream, err := client.Sum(context.Background())
		assert.Nil(t, err)
                // If this assertion is passed, an error will be reported in the following case
		if sendErr := stream.Send(&pingv1.SumRequest{Number: 1}); sendErr != nil {
			assert.ErrorIs(t, err, io.EOF)  // mey sendErr
	                assert.Equal(t, triple.CodeOf(err), triple.CodeUnknown) // mey sendErr
               	}
		err = stream.CloseAndReceive(triple.NewResponse(&pingv1.SumResponse{}))
		assert.Equal(t, triple.CodeOf(err), triple.CodeInvalidArgument)
	})