Abstract base transport class & local transport class

src/samples/foundational/01-say-one-thing.py

@@ -24,7 +24,7 @@ async def main(room_url):
             "Say One Thing",
             meeting_duration_minutes,
         )
-        transport.mic_enabled = True
+        transport._mic_enabled = True
         tts = ElevenLabsTTSService(aiohttp_session=session, api_key=os.getenv("ELEVENLABS_API_KEY"), voice_id=os.getenv("ELEVENLABS_VOICE_ID"))
 
         # Register an event handler so we can play the audio when the participant joins.