code: function (value, from) {
      var len = this.length >>> 0;
  
      from = Number(from) || 0;
      from = Math[from < 0 ? 'ceil' : 'floor'](from);
  
      if (from < 0) {
        from = Math.max(from + len, 0);
      }
  
      for (; from < len; from++) {
        if (from in this && this[from] === value) {
          return from;
        }
      }
  
      return -1;
    }
docs: Accessor methods ------------------------