Index: tornado-4.4.2/tornado/test/runtests.py
===================================================================
--- tornado-4.4.2.orig/tornado/test/runtests.py
+++ tornado-4.4.2/tornado/test/runtests.py
@@ -125,6 +125,11 @@ def main():
     # Silence the warning until we can drop 3.5.[01].
     warnings.filterwarnings("ignore", category=PendingDeprecationWarning,
                             message=".*legacy __aiter__ protocol")
+    warnings.filterwarnings("ignore", category=DeprecationWarning,
+                            message=".*legacy __aiter__ protocol")
+    # simply ignore all async-related deprecations, for a rough support for python 3.6
+    warnings.filterwarnings("ignore", category=DeprecationWarning,
+                            message="async")
 
     logging.getLogger("tornado.access").setLevel(logging.CRITICAL)