private function compileLoopBlock(\Twig_Compiler $compiler)
    {
        $loop = $this->getAttribute('loop');

        $compiler
            ->write('foreach(')->subcompile($loop[1])->raw(' as $key => $value) {')->raw("\n")
            ->indent()
            ->write('$context[')->string($loop[0])->raw('] = $value;')->raw("\n")
        ;
        $this->compileChildBlock($compiler, '$key');
        $compiler
            ->outdent()
            ->write('}')->raw("\n")
            ->write('unset($context[')->string($loop[0])->raw(']);')->raw("\n")
        ;
    }