code: def com_google_fonts_check_metadata_license(family_metadata):
    
    licenses = ["APACHE2", "OFL", "UFL"]
    if family_metadata.license in licenses:
      yield PASS, ("Font license is declared"
                   " in METADATA.pb as \"{}\"").format(family_metadata.license)
    else:
      yield FAIL, ("METADATA.pb license field (\"{}\")"
                   " must be one of the following:"
                   " {}").format(family_metadata.license,
                                 licenses)
docs: METADATA.pb license is "APACHE2", "UFL" or "OFL"?