docs: function indexOf(array, value, fromIndex) {
      var length = array ? array.length : 0;
      if (typeof fromIndex == 'number') {
        fromIndex = fromIndex < 0 ? nativeMax(length + fromIndex, 0) : fromIndex;
      } else {
        fromIndex = 0;
      }
      var index = (fromIndex || 0) - 1,
          isReflexive = value === value;
  
      while (++index < length) {
        var other = array[index];
        if ((isReflexive ? other === value : other !== other)) {
          return index;
        }
      }
      return -1;
    }