Return newly added CT_HdrFtrRef element of *type_* with *rId*.

        The element tag is `w:footerReference`.

def add_footerReference(self, type_, rId):
        """Return newly added CT_HdrFtrRef element of *type_* with *rId*.

        The element tag is `w:footerReference`.
        """
        footerReference = self._add_footerReference()
        footerReference.type_ = type_
        footerReference.rId = rId
        return footerReference