For example, the code of the Popular hashtags of the Posts app will have look like:

array (
 'module' => 'system',
 'method' => 'keywords_cloud',
 'params' => 
 array (
  0 => 'bx_posts',
  1 => 'bx_posts',
  2 => array('max_count' => 36)
 ),
 'class' => 'TemplServiceMetatags',
)