def METHOD_NAME(self, list_of_matrices):
    data = np.zeros(len(self._row))
    assert len(self._maps) == len(list_of_matrices)
    for i, mp in enumerate(self._maps):
        data += mp.dot(list_of_matrices[i].data)
    ret = coo_matrix(
        (data, (np.copy(self._row), np.copy(self._col))), shape=self._shape
    )
    return ret