protected function fileExtension()
    {
        if (!$this->fileExtension) {
            $mimeType = $this->serializer->mimeType();
            $this->fileExtension = $this->mimetypes->fileExtensions($mimeType)[0];
        };
        return $this->fileExtension;
    }
protected function fileExtension()
    {
        if (!$this->fileExtension) {
            $mimeType = $this->serializer->mimeType();
            $this->fileExtension = $this->mimetypes->fileExtensions($mimeType)[0];
        };
        return $this->fileExtension;
    }
protected function fileExtension ( ) { if ( ! $ this -> fileExtension ) { $ mimeType = $ this -> serializer -> mimeType ( ) ; $ this -> fileExtension = $ this -> mimetypes -> fileExtensions ( $ mimeType ) [ 0 ] ; } ; return $ this -> fileExtension ; }
Get the file extension for the cache files

@return string
Get the file extension for the cache files