Return entries although their related objects are missing

[jirzi0]

Is your feature request related to a problem? Please describe.
I want to get eg. documents with related models, however, if the related entry is not present, then the whole "row" goes missing. If I call like so:

{
    "include": [{
        "relation": "members"
    }]
}

then all the results than do not have a corresponding member don't get returned at all.

Describe the solution you'd like
Return all results, even without the related models.
Instead of the missing object, return something else: null, string (n/A), ...(?).

Describe alternatives you've considered
Throw an error.

Additional context
Not something crazy important but it feels awkward.

[henrikjohansson712]

I've just pushed a change that should take care of this. Let me know if it works for you.