array slice last one
npm install xcxerxes-array-lastjavascript
var flatten = require('xcxerxes-array-last')
console.log(flatten([1, [2], [3], 4, [5]]))
// -> [1, 2, 3, 4, 5]
console.log(arrayFirst[[[1]], [2], 3, [4], 5])
// -> [1, 2, 3, 4, 5]
``