def METHOD_NAME():
    stylesheet = tinycss2.parse_stylesheet(
        '@font-face {'
        '  font-family: Gentium Hard;'
        '  src: local();'
        '}')
    at_rule, = stylesheet
    assert at_rule.at_keyword == 'font-face'
    font_family, src = list(preprocess_descriptors(
        'font-face', 'https://weasyprint.org/foo/',
        tinycss2.parse_declaration_list(at_rule.content)))
    assert font_family == ('font_family', 'Gentium Hard')
    assert src == ('src', (('local', None),))