def _process_event(self, event):
        """Process received events.

        Process events received, applying normalization for those
        events referencing a new or changed file and only if it's
        not the result of a previous normalization.

        Args:
            event: Event to process.
        """
        if (not event.is_directory and
                not event.src_path.endswith(BATCH_EXTENSION)):
            self._logger.info('Detected file change: %s', event.src_path)
            self._batch.process_file(event.src_path)