async def _flush_aggregation(self):
        """Flush the current aggregation as a TranscriptionFrame."""
        if not self._aggregation:
            return

        sequence = self._aggregation
        transcription_text = f"{self._prefix}{sequence}"

        transcription_frame = TranscriptionFrame(
            text=transcription_text, user_id="", timestamp=time_now_iso8601()
        )
        await self.push_frame(transcription_frame)

        self._aggregation = ""
Flush the current aggregation as a TranscriptionFrame.
src/pipecat/processors/aggregators/dtmf_aggregator.py