def _on_file_deleted(self, event: FileSystemEvent):
if not event.is_directory and self.is_data_file(event.src_path):<EOL><INDENT>assert event.src_path in self._origin_mapped_data<EOL>del(self._origin_mapped_data[event.src_path])<EOL>self.notify_listeners(FileSystemChange.DELETE)<EOL><DEDENT>
Called when a file in the monitored directory has been deleted.
:param event: the file system event