/**
  * Initializes the underlying template engine.
  */
 function __construct(WebSoccer $env, I18n $i18n, ViewHandler $viewHandler = null)
 {
     $this->_skin = $env->getSkin();
     $this->_initTwig();
     $this->_environment->addGlobal(I18N_GLOBAL_NAME, $i18n);
     $this->_environment->addGlobal(ENVIRONMENT_GLOBAL_NAME, $env);
     $this->_environment->addGlobal(SKIN_GLOBAL_NAME, $this->_skin);
     $this->_environment->addGlobal(VIEWHANDLER_GLOBAL_NAME, $viewHandler);
 }