Pass code check.

examples/treeping64.py

@@ -2,7 +2,6 @@
 
 "Create a 64-node tree network, and test connectivity using ping."
 
-from mininet.cli import CLI
 from mininet.log import setLogLevel
 from mininet.net import init, Mininet
 from mininet.node import KernelSwitch, UserSwitch, OVSKernelSwitch
@@ -14,6 +13,8 @@ def TreeNet( depth=1, fanout=2, **kwargs ):
     return Mininet( topo, **kwargs )
 
 def treePing64():
+    "Run ping test on 64-node tree networks."
+
     results = {}
     switches = { 'reference kernel': KernelSwitch,
         'reference user': UserSwitch,