callback hell
15 minutes12 secondspromise status
17 minutes56 secondsresult of promise
04 minutes40 secondsparameters of then method
09 minutes10 secondsthen method gets data
07 minutes28 secondsthen method return value
09 minutes31 secondsReturns the status change of the instance
16 minutes36 secondscatch method
10 minutes24 secondsSolving callback hell
14 minutes56 secondsOptimize code
07 minutes16 seconds