protected function get_thumbnail_url($filepath, $thumbsize, $token) {
        return moodle_url::make_pluginfile_url($this->context->id, 'repository_filesystem', $thumbsize, $this->id,
                '/' . trim($filepath, '/') . '/', $token);
    }
protected function get_thumbnail_url($filepath, $thumbsize, $token) {
        return moodle_url::make_pluginfile_url($this->context->id, 'repository_filesystem', $thumbsize, $this->id,
                '/' . trim($filepath, '/') . '/', $token);
    }
protected function get_thumbnail_url ( $ filepath , $ thumbsize , $ token ) { return moodle_url :: make_pluginfile_url ( $ this -> context -> id , 'repository_filesystem' , $ thumbsize , $ this -> id , '/' . trim ( $ filepath , '/' ) . '/' , $ token ) ; }
Returns url of thumbnail file.

@param string $filepath current path in repository (dir and filename)
@param string $thumbsize 'thumb' or 'icon'
@param string $token identifier of the file contents - to prevent browser from caching changed file
@return moodle_url
Returns url of thumbnail file .