'Iterate over queryset objects and return User objects
This allows for non-User querysets to pass back a list of Users to send
to. By default, assume we\'re working with :py:class:`User` objects and
just yield the single object.
For example, this could be made to return project owners with::
for owner in project.users.all():
yield owner
:param obj: object from queryset, type is dependent on model class
:rtype: django.contrib.auth.models.User'

def get_object_recipients(self, obj):

    (yield obj)
