src/Controller/Plugin/ContentCollector.php
public function trigger($event, $target = null)
    {
        if (empty($this->_template) || !is_string($this->_template)) {
            throw new \InvalidArgumentException('ContentCollector must have a template-name');
        }
          
        $responseCollection = $this->getController()->getEventManager()->trigger($event, $target);
        $viewModel = new ViewModel();
        $viewModel->setTemplate($this->_template);
        foreach ($responseCollection as $i => $response) {
            if (is_string($response)) {
                $template = $response;
                $response = new ViewModel(array('target' => $target));
                $response->setTemplate($template);
            }
            $viewModel->addChild($response, $this->_captureTo . $i);
        }
                
        return $viewModel;
    }
public function trigger($event, $target = null)
    {
        if (empty($this->_template) || !is_string($this->_template)) {
            throw new \InvalidArgumentException('ContentCollector must have a template-name');
        }
          
        $responseCollection = $this->getController()->getEventManager()->trigger($event, $target);
        $viewModel = new ViewModel();
        $viewModel->setTemplate($this->_template);
        foreach ($responseCollection as $i => $response) {
            if (is_string($response)) {
                $template = $response;
                $response = new ViewModel(array('target' => $target));
                $response->setTemplate($template);
            }
            $viewModel->addChild($response, $this->_captureTo . $i);
        }
                
        return $viewModel;
    }
Trigger capture event

@param   EventInterface $event
@param   mixed|null  $target

@return  ViewModel