Tornado update

libs/tornado/platform/posix.py

@@ -16,13 +16,12 @@
 
 """Posix implementations of platform-specific functionality."""
 
-from __future__ import absolute_import, division, with_statement
+from __future__ import absolute_import, division, print_function, with_statement
 
 import fcntl
 import os
 
 from tornado.platform import interface
-from tornado.util import b
 
 
 def set_close_exec(fd):
@@ -53,7 +52,7 @@ class Waker(interface.Waker):
 
     def wake(self):
         try:
-            self.writer.write(b("x"))
+            self.writer.write(b"x")
         except IOError:
             pass