public async Task Process_GiftBoxUpdateForNonexistentCartLine_ShouldReturnValidationErrorMessage()
{
_findEntityPipelineMock
.Setup(p => p.Run(It.IsAny <FindEntityArgument>(), It.IsAny <CommercePipelineExecutionContextOptions>()))
.Returns(Task.FromResult((CommerceEntity)CreateInputCart("WrongCartLine1")));
var outputCart = await _command.Process(_commerceContextFake, TestCartId, TestCartLineId, true);
var errorMessage = _commerceContextFake.GetMessage(m => m.Code == new KnownResultCodes().ValidationError);
Assert.NotNull(errorMessage);
}