const {AsyncLock}   = require('lock')
const lock = AsyncLock()
lock(['A', 'B', 'C'], function(){
    //do an async operation
    return someAsyncOperation(args)
    
}).then(function(result){
  //A, B & C are now unlocked!
}).catch(function(e){ 
// error thrown by someAsyncOperation(args) 
})