Explicitly read the configuration files.

        Reads all configuration files in this Parameters object.  Even if
        inotify is watching or a read has already occurred.

        .. note::

           The order that the configuration files are read is not guaranteed.

def read_configuration_files(self):
        '''Explicitly read the configuration files.

        Reads all configuration files in this Parameters object.  Even if
        inotify is watching or a read has already occurred.

        .. note::

           The order that the configuration files are read is not guaranteed.

        '''

        for file_name, configuration_parser in self.configuration_files.items():
            if os.access(file_name, os.R_OK):
                configuration_parser.read(file_name)
            else:
                logger.warn('could not read %s', file_name)
                warnings.warn('could not read {}'.format(file_name), ResourceWarning)