Fix typo: afe -> safe in add_callback_from_signal docstring

diff --git a/tornado/ioloop.py b/tornado/ioloop.py
index ec93518d0e6aab582a05119b6e5c742cb2e6bb6f..d0965f8e427ac18440904634694abd86cad88c1b 100644 (file)
--- a/tornado/ioloop.py
+++ b/tornado/ioloop.py
@@ -654,7 +654,7 @@ class IOLoop(Configurable):
     ) -> None:
         """Calls the given callback on the next I/O loop iteration.
 
-        Intended to be afe for use from a Python signal handler; should not be
+        Intended to be safe for use from a Python signal handler; should not be
         used otherwise.
 
         .. deprecated:: 6.4