def METHOD_NAME(self, cubes, i_dim):
    """Add a mesh to one dim of the 'normal case' test-cubes."""
    for cube in cubes:
        n_size = cube.shape[i_dim]
        mesh = sample_mesh(n_nodes=n_size, n_faces=n_size, n_edges=0)
        for co in mesh.to_MeshCoords("face"):
            cube.add_aux_coord(co, i_dim)
        assert cube.mesh is not None