def METHOD_NAME():
    from temboardui.toolkit.configuration import (
        MergedConfiguration, OptionSpec, UserError,
        iter_defaults,
    )
    spec = OptionSpec('section', 'req', default=OptionSpec.REQUIRED)
    config = MergedConfiguration(specs=[spec])
    assert not list(iter_defaults(config.specs))
    with pytest.raises(UserError):
        config.check_required()