protected function printErrorLevel(Output $output)
 {
     $fatals = $output->getMessageCount(Output::FATAL);
     $errors = $output->getMessageCount(Output::ERROR);
     $warnings = $output->getMessageCount(Output::WARNING);
     $notices = $output->getMessageCount(Output::NOTICE);
     if ($fatals > $this->numFatal) {
         $this->output->write("<fatal>F</fatal>");
     } else {
         if ($errors > $this->numError) {
             $this->output->write("<error>E</error>");
         } else {
             if ($warnings > $this->numWarning) {
                 $this->output->write("<warning>W</warning>");
             } else {
                 if ($notices > $this->numNotice) {
                     $this->output->write("<notice>N</notice>");
                 } else {
                     $this->output->write(".");
                 }
             }
         }
     }
     $this->progress++;
     if ($this->progress % (79 - $this->progressLength) == 0) {
         $this->output->write(' ' . sprintf('%' . strlen($this->maxProgress) . 's', $this->progress));
         $this->output->write(' / ' . $this->maxProgress);
         $this->output->writeln(' (' . sprintf('%3s', floor(100 * ($this->progress / $this->maxProgress))) . '%)');
     }
     $this->numFatal = $fatals;
     $this->numError = $errors;
     $this->numWarning = $warnings;
     $this->numNotice = $notices;
 }