def check_common_names():
    common_names_missing = (set(COMMON_NAMES) - set(COUNTRIES))
    if common_names_missing:
        print('')
        print('The following common names do not match an official country code:')
        for code in sorted(common_names_missing):
            print('  {0}'.format(code))
def check_common_names():
    common_names_missing = (set(COMMON_NAMES) - set(COUNTRIES))
    if common_names_missing:
        print()
        print('The following common names do not match an official country code:')
        for code in sorted(common_names_missing):
            print('  {0}'.format(code))