Break loop after result retreival

Author: goodboy

tractor/_streaming.py

@@ -272,9 +272,9 @@ async def aclose(self):
     @asynccontextmanager
     async def subscribe(
         self,
-
     ) -> AsyncIterator[BroadcastReceiver]:
-        '''Allocate and return a ``BroadcastReceiver`` which delegates
+        '''
+        Allocate and return a ``BroadcastReceiver`` which delegates
         to this message stream.
 
         This allows multiple local tasks to receive each their own copy
@@ -674,6 +674,7 @@ def consume(
                             result = consume(msg)
                             if result:
                                 self._result = result
+                                break
 
                 if not self._result:
                     while True: