def METHOD_NAME(self, model, cov_func, X1, drop_first):
    n_basis = 100
    with model:
        gp = pm.gp.HSGP(m=[n_basis], c=4.0, cov_func=cov_func, drop_first=drop_first)
        gp.prior("f1", X1)
        n_coeffs = model.f1_hsgp_coeffs_.type.shape[0]
        if drop_first:
            assert (
                n_coeffs == n_basis - 1
            ), f"one basis vector should have been dropped, {n_coeffs}"
        else:
            assert n_coeffs == n_basis, "one was dropped when it shouldn't have been"