class UserKwargModelFormMixin:
    """
    Generic model form mixin for popping user out of the kwargs and
    attaching it to the instance.

    This mixin must precede forms.ModelForm/forms.Form. The form is not
    expecting these kwargs to be passed in, so they must be popped off before
    anything else is done.
    """

    def __init__(self, *args, **kwargs):
        """Remove the user from **kwargs and assign it on the object"""
        self.user = kwargs.pop("user", None)
        super().__init__(*args, **kwargs)