function shuffleArray_(array) {
  let clone = array.slice(0);
  for (let i = clone.length - 1; i > 0; i--) {
    let j = Math.floor(Math.random() * (i + 1));
    let temp = clone[i];
    clone[i] = clone[j];
    clone[j] = temp;
  }
  return clone;
}
Copies and randomizes an array.

@param {object[]} array - Array to shuffle
@return {object[]} randomized copy of the array