The science of Promise Chaining in Javascript
if Nayan fails to reply, exception handled by "you Know :)"
RequestForBook.then(()=> receiveBook()).catch(noBookReceivedError => callNayan())
RequestThroughMailForBook.then(()=> receiveBook()).catch(noBookReceivedError => nayanComesToYourHomeToDeliver())
if Nayan fails to reply, exception handled by "you Know :)"
RequestForBook.then(()=> receiveBook()).catch(noBookReceivedError => callNayan())
RequestThroughMailForBook.then(()=> receiveBook()).catch(noBookReceivedError => nayanComesToYourHomeToDeliver())