def METHOD_NAME(self):
    # Set values
    model = UnitsMapping(
        ((u.m, None),),
        input_units_equivalencies="test_eqiv",
        input_units_allow_dimensionless=True,
        name="test",
    )
    assert model._mapping == ((u.m, None),)
    assert model._input_units_strict == {"x": True}
    assert model.input_units_equivalencies == "test_eqiv"
    assert model.input_units_allow_dimensionless == {"x": True}
    assert model.name == "test"
    assert model._input_units == {"x": u.m}
    # Default values
    model = UnitsMapping(((u.K, None),))
    assert model._mapping == ((u.K, None),)
    assert model._input_units_strict == {"x": True}
    assert model.input_units_equivalencies is None
    assert model.input_units_allow_dimensionless == {"x": False}
    assert model.name is None
    assert model._input_units == {"x": u.K}
    # Error
    MESSAGE = r"If one return unit is None, then all must be None"
    with pytest.raises(ValueError, match=MESSAGE):
        UnitsMapping(((u.m, None), (u.m, u.K)))