code: public function start($type = self::TYPE_INFO, array $options = array())
      {
          if ($this->captureLock) {
              throw new \RuntimeException('Cannot start capture, there is already a capture running.');
          }
          $this->captureLock    = true;
          $this->captureType    = $type;
          $this->captureOptions = $options;
          ob_start();
  
          return $this;
      }
docs: Starts content capturing.
  
  @param string|array $type
  @param array        $options see {@łink render()} for information.
  
  @return self
  @throws \RuntimeException if there's already another capturing process running.