code: private function getTemplatePath()
      {
          /**
           * @var $tsfe TypoScriptFrontendController
           */
          $tsfe = $GLOBALS['TSFE'];
          if (isset($tsfe->tmpl->setup['lib.']['plugins.']['tx_happyfeet.']['view.']['template'])) {
              $templateFile = GeneralUtility::getFileAbsFileName(
                  $tsfe->tmpl->setup['lib.']['plugins.']['tx_happyfeet.']['view.']['template']
              );
              if (is_file($templateFile)) {
                  return $tsfe->tmpl->setup['lib.']['plugins.']['tx_happyfeet.']['view.']['template'];
              }
          }
  
          return $this->getTemplatePathAndFilename($this->defaultTemplate);
      }
docs: checks if a alternative template is defined via typoscript setup configuration and if it exists as a file
  
  @return string