def test_invalid_scalar_index(adata, index):
    # https://github.com/theislab/anndata/issues/619
    with pytest.raises(IndexError, match=r".*index.* out of range\."):
        _ = adata[index]
def pop(self, key, default=None):
        value = self._collection.pop(key, default)
        if isinstance(value, Proxy):
            value = value.get()
        return value