Does it mutate 😱
Array.prototype.push
Mutates
Description
The push() method adds one or more elements to the end of an array and returns the new length of the array.
Array.prototype.push ( [ item1 [ , item2 [ , … ] ] ] )https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/push
Example
var animals = ['pigs', 'goats', 'sheep'];
console.log(animals.push('cows'));
// expected output: 4
console.log(animals);
// expected output: Array ["pigs", "goats", "sheep", "cows"]
animals.push('chickens');
console.log(animals);
// expected output: Array ["pigs", "goats", "sheep", "cows", "chickens"]