Terminate async gen example caller to avoid (benign) errors in console output

examples/asynchronous_generators.py

@@ -1,23 +1,20 @@
+from typing import AsyncIterator
 from itertools import repeat
+
 import trio
 import tractor
 
-tractor.log.get_console_log("INFO")
 
+async def stream_forever() -> AsyncIterator[int]:
 
-async def stream_forever():
     for i in repeat("I can see these little future bubble things"):
-        # each yielded value is sent over the ``Channel`` to the
-        # parent actor
+        # each yielded value is sent over the ``Channel`` to the parent actor
         yield i
         await trio.sleep(0.01)
 
 
 async def main():
 
-    # stream for at most 1 seconds
-    with trio.move_on_after(1) as cancel_scope:
-
     async with tractor.open_nursery() as n:
 
         portal = await n.start_actor(
@@ -28,12 +25,17 @@ async def main():
         # this async for loop streams values from the above
         # async generator running in a separate process
         async with portal.open_stream_from(stream_forever) as stream:
+            count = 0
             async for letter in stream:
                 print(letter)
+                count += 1
 
-    # we support trio's cancellation system
-    assert cancel_scope.cancelled_caught
-    assert n.cancelled
+                if count > 50:
+                    break
+
+        print('stream terminated')
+
+        await portal.cancel_actor()
 
 
 if __name__ == '__main__':