Provided test for the pull request #471

I provided a couple of test for the pull request #471.

Although when I created the test I've realised from another potential issue when I wrote a test; I've realised that although ```detect_buffers``` is enable, it doesn't apply for ```multi``` command, it also return strings or numbers, so I left that test commented to pass them, because the issue reported with the pull request #471 is fixed and that other one may be another issue and so far we may consider that ```detect_buffers``` doesn't do any thing in multi command.