Strip documentation about removed argument

diff --git a/tornado/web.py b/tornado/web.py
index 7d75b35d79f9b785125836bd0a9f806b6a8c57a3..adbf591e50283b845ee30843485483534c85ce37 100644 (file)
--- a/tornado/web.py
+++ b/tornado/web.py
@@ -1056,12 +1056,6 @@ class RequestHandler(object):
     def flush(self, include_footers: bool = False) -> "Future[None]":
         """Flushes the current output buffer to the network.
 
-        The ``callback`` argument, if given, can be used for flow control:
-        it will be run when all flushed data has been written to the socket.
-        Note that only one flush callback can be outstanding at a time;
-        if another flush occurs before the previous flush's callback
-        has been run, the previous callback will be discarded.
-
         .. versionchanged:: 4.0
            Now returns a `.Future` if no callback is given.