def test_negative_scalar_index(adata, index: int, obs: bool):
    pos_index = index + (adata.n_obs if obs else adata.n_vars)

    if obs:
        adata_pos_subset = adata[pos_index]
        adata_neg_subset = adata[index]
    else:
        adata_pos_subset = adata[:, pos_index]
        adata_neg_subset = adata[:, index]

    np.testing.assert_array_equal(
        adata_pos_subset.obs_names, adata_neg_subset.obs_names
    )
    np.testing.assert_array_equal(
        adata_pos_subset.var_names, adata_neg_subset.var_names
    )
def remove_backend(self, backend_id):
        """ Removes a backend from the treeview, and selects the first (to show
        something in the configuration panel

        @param backend_id: the id of the backend to remove
        """
        if backend_id in self.backendid_to_iter:
            self.liststore.remove(self.backendid_to_iter[backend_id])
            del self.backendid_to_iter[backend_id]
            self.select_backend()