def __init__(self, to, field_name, related_name=None, limit_choices_to=None,
        parent_link=False, on_delete=None):
        try:
            to._meta
        except __HOLE__:  # to._meta doesn't exist, so it must be RECURSIVE_RELATIONSHIP_CONSTANT
            assert isinstance(to, six.string_types), "'to' must be either a model, a model name or the string %r" % RECURSIVE_RELATIONSHIP_CONSTANT
        self.to, self.field_name = to, field_name
        self.related_name = related_name
        if limit_choices_to is None:
            limit_choices_to = {}
        self.limit_choices_to = limit_choices_to
        self.multiple = True
        self.parent_link = parent_link
        self.on_delete = on_delete
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/django/db/models/fields/related.py/ManyToOneRel.__init__