code: function(index) {
        index = Math.min(index, this.length);
        arguments.length > 1
        && this.splice.apply(this, [index, 0].concat([].pop.call(arguments)))
        && this.insert.apply(this, arguments);
        return this;
      }
docs: Syntax:
  array.insert(index, value1, value2, ..., valueN)
  @param {Number} index where item will be inserted, if bigger than length of an array, will be inserted at the end of an array, not
  @param [...] unlimited amount of values to insert
  @returns {Array}