add stateless case

examples/speech_to_speech/english_alternate_agent.py

@@ -1,3 +1,5 @@
+from typing import Optional
+from simuleval.agents.states import AgentStates
 from simuleval.utils import entrypoint
 from simuleval.data.segments import SpeechSegment
 from simuleval.agents import SpeechToSpeechAgent
@@ -50,7 +52,10 @@ def __init__(self, args):
     def add_args(parser):
         parser.add_argument("--wait-seconds", default=1, type=int)
 
-    def policy(self):
+    def policy(self, states: Optional[AgentStates] = None):
+        if states is None:
+            states = states
+
         length_in_seconds = round(
             len(self.states.source) / self.states.source_sample_rate
         )