<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def parse_config_files(self, filenames=None, ignore_option_errors=False):
 """Parses configuration files from various levels and loads configuration. """

        self._parse_config_files(filenames=filenames)

        parse_configuration(self, self.command_options,
                            ignore_option_errors=ignore_option_errors)
        self._finalize_requires()