docs: function (callback, invert) {
              var callbackInverse,
                  matches = [],
                  i = 0,
                  length = this.length,
                  callbackExpect = !invert;
  
              // Go through the array, only saving the items
              // that pass the validator function
              for (; i < length; i++) {
                  callbackInverse = !callback(this[i], i);
                  if (callbackInverse !== callbackExpect) {
                      matches.push(this[i]);
                  }
              }
  
              return matches;
          }