Remove unused import

diff --git a/tornado/websocket.py b/tornado/websocket.py
index b536c3ced99291470b4ed367036e6da242f9798b..738a9ccb80013296de53107df1ef35e092532482 100644 (file)
--- a/tornado/websocket.py
+++ b/tornado/websocket.py
@@ -19,7 +19,6 @@ the protocol (known as "draft 76") and are not compatible with this module.
 from __future__ import absolute_import, division, print_function
 
 import base64
-import collections
 import hashlib
 import os
 import struct