docs: function arrayContains(array, element) {
      var i = -1,
          length = array.length;
  
      // Special handling for NaN
      if (element !== element) {
        while (++i < length) {
          if (array[i] !== array[i]) {
            return true;
          }
        }
        return false;
      }
  
      while (++i < length) {
        if (array[i] === element) {
          return true;
        }
      }
      return false;
    }