public function push($value, $key = null)
    {
        if ($key == null) {
            $this->storage[] = $value;
        } else {
            $this->storage[$key] = $value;
        }

        return $this;
    }
public function push($value, $key = null)
    {
        if ($key == null) {
            $this->storage[] = $value;
        } else {
            $this->storage[$key] = $value;
        }

        return $this;
    }
public function push ( $ value , $ key = null ) { if ( $ key == null ) { $ this -> storage [ ] = $ value ; } else { $ this -> storage [ $ key ] = $ value ; } return $ this ; }
Add after the last item in the collection

@param  mixed      $value
@param  int|string $key

@return mixed
Add after the last item in the collection