From 76f20eca91a754530539958323df8758fb09d814 Mon Sep 17 00:00:00 2001
From: Ben Darnell <ben@bendarnell.com>
Date: Sun, 18 Jan 2015 11:35:20 -0500
Subject: [PATCH] Document PeriodicCallback.is_running.

---
 tornado/ioloop.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tornado/ioloop.py b/tornado/ioloop.py
index 52b73ad5b..bbe74a15a 100644
--- a/tornado/ioloop.py
+++ b/tornado/ioloop.py
@@ -970,6 +970,10 @@ class PeriodicCallback(object):
             self._timeout = None
 
     def is_running(self):
+        """Return True if this `.PeriodicCallback` has been started.
+
+        .. versionadded:: 4.1
+        """
         return self._running
 
     def _run(self):
-- 
2.47.3