Create a new pivot model instance.

def new_pivot(self, attributes=None, exists=False):
        """
        Create a new pivot model instance.
        """
        from .morph_pivot import MorphPivot

        pivot = MorphPivot(self._parent, attributes, self._table, exists)

        pivot.set_pivot_keys(self._foreign_key, self._other_key).set_morph_type(
            self._morph_type
        ).set_morph_name(self._morph_name)

        return pivot