Clarify functions that can only be called once
Clarify functions that can only be called once

odo/cowboy,Reimerei/cowboy,acrispin/cowboy,nviennot/cowboy,K2InformaticsGmbH/cowboy,turtleDeng/cowboy,yangchengjian/cowboy,yangchengjian/cowboy,noname007/cowboy,imdeps/cowboy,binarin/cowboy,kivra/cowboy,hairyhum/cowboy,bobos/ecweb,manastech/cowboy,bsmr-erlang/cowboy,sile/cowboy,cad627/cowboy,276361270/cowboy,ninenines/cowboy,CrankWheel/cowboy,pap/cowboy,callsign-core/cowboy_hybi00,paulperegud/cowboy,rabbitmq/cowboy,manastech/cowboy,grahamrhay/cowboy,layerhq/cowboy,callsign-core/cowboy_hybi00,layerhq/cowboy,cad627/cowboy,dangjun625/cowboy,omusico/cowboy,binarin/cowboy