def test_deepcopy_subset(adata, spmat: type):
    adata.obsp["arr"] = np.zeros((adata.n_obs, adata.n_obs))
    adata.obsp["spmat"] = spmat((adata.n_obs, adata.n_obs))

    adata = deepcopy(adata[:10].copy())

    assert isinstance(adata.obsp["arr"], np.ndarray)
    assert not isinstance(adata.obsp["arr"], ArrayView)
    np.testing.assert_array_equal(adata.obsp["arr"].shape, (10, 10))

    assert isinstance(adata.obsp["spmat"], spmat)
    assert not isinstance(
        adata.obsp["spmat"],
        SparseCSRView if spmat is sparse.csr_matrix else SparseCSCView,
    )
    np.testing.assert_array_equal(adata.obsp["spmat"].shape, (10, 10))
def _create_3d_axis():
    """creates a subplot with 3d projection if one does not already exist"""
    from matplotlib.projections import get_projection_class
    from matplotlib import _pylab_helpers

    create_axis = True
    if _pylab_helpers.Gcf.get_active() is not None:
        if isinstance(plt.gca(), get_projection_class('3d')):
            create_axis = False
    if create_axis:
        plt.figure()
        plt.subplot(111, projection='3d')