How to use the catalogue._remove function in catalogue

assert len(catalogue.REGISTRY) == 1
    assert ("a", "b", "c") in catalogue.REGISTRY
    assert catalogue.check_exists("a", "b", "c")
    assert catalogue.REGISTRY[("a", "b", "c")] == "test"
    assert catalogue._get(("a", "b", "c")) == "test"
    with pytest.raises(catalogue.RegistryError):
        catalogue._get(("a", "b", "d"))
    with pytest.raises(catalogue.RegistryError):
        catalogue._get(("a", "b", "c", "d"))
    catalogue._set(("x", "y", "z1"), "test1")
    catalogue._set(("x", "y", "z2"), "test2")
    assert catalogue._remove(("a", "b", "c")) == "test"
    catalogue._set(("x", "y2"), "test3")
    with pytest.raises(catalogue.RegistryError):
        catalogue._remove(("x", "y"))
    assert catalogue._remove(("x", "y", "z2")) == "test2"