code: function arrayify(thing) {
      if (Array.isArray(thing)) {
        return thing;
      }
  
      if (thing && typeof thing.length === 'number') {
        return Array.from(thing);
      }
  
      return [thing];
    }
docs: If the first parameter is not an array, return an array containing the first
  parameter.
  @param {*} thing Anything.
  @return {Array.<*>} Array of things.