@staticmethod<EOL><INDENT>def _read_configuration(config_filename):<DEDENT>
config = ConfigParser()<EOL>config.read(config_filename)<EOL>if '<STR_LIT>' in config['<STR_LIT>']:<EOL><INDENT>path = os.path.dirname(config_filename) + '<STR_LIT:/>' + config.get('<STR_LIT>', '<STR_LIT>')<EOL>config_supplement = ConfigParser()<EOL>config_supplement.read(path)<EOL><DEDENT>else:<EOL><INDENT>config_supplement = None<EOL><DEDENT>return config, config_supplement<EOL>
Checks the supplement file.

:param str config_filename: The name of the configuration file.

:rtype: (configparser.ConfigParser,configparser.ConfigParser)