Handle request with empty list exceptions

[qnbhd]

Related: https://github.com/qnbhd/deployme/issues/91

If, with the current implementation, send a request of the form:

{
    "data": []
}

or

{
    "data": [[]]
}

different models may respond differently to this request. you need to add error handling and maybe write a fuzzy test.

СС: @pacifikus