call site 0 for execnet.Channel.next
execnet/testing/test_gateway.py - line 180
175
176
177
178
179
180
181
   def test_channel_iter(self):
       channel = self.gw.remote_exec("""
                 for x in range(3): 
                   channel.send(x)
           """) 
->     l = list(channel) 
       assert l == range(3)