access a key of object safely
npm i key-accessor --save
import keyAccessor from 'key-accessor'
const music = {
rock: {
band: 'G N\' R'
},
pop: {
}
}
const obj = keyAccessor(music)
obj.rock.band() // output: G N' R
obj.pop.band() // output: undefined
obj.classical.band() // output: undefined
NOT support IE, since depending on Proxy object (ES6)