merge
Merge branch 'raven' of https://github.com/ludwiksh/Etales
Merge branch 'raven' of https://github.com/ludwiksh/Etales
improve negotiation
merge
start to fix promise
Merge branch 'master' of https://github.com/ludwiksh/Etales into raven
merge from master
producer step1 finish
step 2 finish
producer step 3 finish
producer finish
retailer step 3
retailer 3 finish