def create_friendship_instance(sender, instance, created, raw, **kwargs):
    """
    Create a |FriendshipRequest| for newly created |User|.

    .. seealso::
        :data:`~django.db.models.signals.post_save` built-in signal.
    """
    from friends.models import Friendship
    if created and not raw:
        Friendship.objects.create(user=instance)
