code: public function generateAjax($folder, $strField, $level, $mount = false)
      {
          return parent::generateAjax($folder, $this->strField, $level, $mount);
      }
docs: Generate a particular sub part of the file tree and return it as HTML string.
  
  @param string $folder   The folder name.
  
  @param string $strField The property name.
  
  @param int    $level    The level where the given folder shall be rendered within.
  
  @param bool   $mount    Flag determining if the passed folder shall be handled as root level
  (optional, default: no).
  
  @return string
  
  @SuppressWarnings(PHPMD.UnusedFormalParameter)