public function filter(\Closure $c)
 {
     $bpl = [];
     $chunks = [];
     if ($this->blockParameterList !== null) {
         $bpl = $this->blockParameterList->filter($c);
     }
     if ($this->chunks !== null) {
         $chunks = $this->chunks->filter($c);
     }
     return array_merge($bpl, $chunks);
 }