def test_view_mixin_copies_data(adata, array_type: type, attr):
    N = 100
    adata = ad.AnnData(
        obs=pd.DataFrame(index=np.arange(N)), var=pd.DataFrame(index=np.arange(N))
    )

    X = array_type(sparse.eye(N, N).multiply(np.arange(1, N + 1)))
    if attr == "X":
        adata.X = X
    else:
        getattr(adata, attr)["arr"] = X

    view = adata[:50]

    if attr == "X":
        arr_view = view.X
    else:
        arr_view = getattr(view, attr)["arr"]

    arr_view_copy = arr_view.copy()

    if sparse.issparse(X):
        assert not np.shares_memory(arr_view.indices, arr_view_copy.indices)
        assert not np.shares_memory(arr_view.indptr, arr_view_copy.indptr)
        assert not np.shares_memory(arr_view.data, arr_view_copy.data)

        arr_view_copy.data[0] = -5
        assert not np.array_equal(arr_view_copy.data, arr_view.data)
    else:
        assert not np.shares_memory(arr_view, arr_view_copy)

        arr_view_copy[0, 0] = -5
        assert not np.array_equal(arr_view_copy, arr_view)
def select_backend(self, backend_id=None):
        """
        Selects the backend corresponding to backend_id.
        If backend_id is none, refreshes the current configuration panel.

        @param backend_id: the id of the backend to select
        """
        selection = self.get_selection()
        if backend_id in self.backendid_to_iter:
            backend_iter = self.backendid_to_iter[backend_id]
            if selection:
                selection.select_iter(backend_iter)
        else:
            if self._get_selected_path():
                # We just reselect the currently selected entry
                self.on_select_row()
            else:
                # If nothing is selected, we select the first entry
                if selection:
                    selection.select_path("0")
        self.dialog.on_backend_selected(self.get_selected_backend_id())