def METHOD_NAME() -> None:
    expected = xr.Dataset(
        dict(a=2 * np.arange(5)), coords=dict(x=("x", np.arange(5), dict(units="s")))
    )
    class CustomBackend(xr.backends.BackendEntrypoint):
        def open_dataset(
            self,
            filename_or_obj,
            drop_variables=None,
            **kwargs,
        ) -> xr.Dataset:
            return expected.copy(deep=True)
    actual = xr.open_dataset("fake_filename", engine=CustomBackend)
    assert_identical(expected, actual)