anchor.diff:  start_listener(Ref, NbAcceptors, Transport, TransOpts, Protocol, ProtoOpts)
   		when is_integer(NbAcceptors) andalso is_atom(Transport)
   		andalso is_atom(Protocol) ->
  -	supervisor:start_child(cowboy_sup,
  -		{{cowboy_listener_sup, Ref}, {cowboy_listener_sup, start_link, [
  -			NbAcceptors, Transport, TransOpts, Protocol, ProtoOpts
  -		]},
  -		permanent, 5000, supervisor, [cowboy_listener_sup]}).
  +	supervisor:start_child(cowboy_sup, child_spec(Ref, NbAcceptors,
  +		Transport, TransOpts, Protocol, ProtoOpts)).
   
   %% @doc Stop a listener identified by <em>Ref</em>.
   %% @todo Currently request processes aren't terminated with the listener.
  
positive.code: 		{error, Reason} ->
  			{error, Reason}
  	end.
  
negative.code: %% @doc Cowboy API to start and stop listeners.
  -module(cowboy).
  
  -export([start_listener/6, stop_listener/1, child_spec/6]).
  
  %% @doc Start a listener for the given transport and protocol.
  %%
  