<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 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)