code: public function partition(Closure $p)
      {
          $array = $this->toArray();
          $this->collection->clear();
          
          foreach ($array as $key => $element) {
              $this->collection->set($key, $element);
          }
          
          $partitions = $this->collection->partition($p);
          
          return [new static($partitions[0]), new static($partitions[1])];
      }
docs: {@inheritDoc}