original_string: public function concat($source)
      {
          $result = new static($this);
  
          foreach ($source as $item) {
              $result->push($item);
          }
  
          return $result;
      }
code: public function concat($source)
      {
          $result = new static($this);
  
          foreach ($source as $item) {
              $result->push($item);
          }
  
          return $result;
      }
code_tokens: public function concat ( $ source ) { $ result = new static ( $ this ) ; foreach ( $ source as $ item ) { $ result -> push ( $ item ) ; } return $ result ; }
docstring: Push all of the given items onto the collection.
  
  @param  iterable  $source
  @return static
docstring_tokens: Push all of the given items onto the collection .