Constructor.
FragmentRendererInterface[] $renderers An array of FragmentRendererInterface instances:
Boolean $debug Whether the debug mode is enabled or not:
public function __construct(array $renderers = array(), $debug = false) {
  $this->renderers = array();
  foreach ($renderers as $renderer) {
    $this
      ->addRenderer($renderer);
  }
  $this->debug = $debug;
}