Update distributed/worker_memory.py

distributed/worker_memory.py

@@ -140,7 +140,7 @@ def __init__(
         ):
             assert self.memory_monitor_interval is not None
             pc = PeriodicCallback(
-                # Don't store worker ar self.worker to avoid creating a circular
+                # Don't store worker as self.worker to avoid creating a circular
                 # dependency. We could have alternatively used a weakref.
                 # FIXME annotations: https://github.com/tornadoweb/tornado/issues/3117
                 partial(self.memory_monitor, worker),  # type: ignore