models-continent.php

public function populateObjects(&$item)
{
	// Load XRef Countries
	$this->loadXref($item, 'countries', 'countries', 'continent', 'id',
	
// BEGIN
 
    array(
	  	'cities',		          // xref.countries.cities
  		'cities.travellers'	  // xref.countries.cities.travellers
	  )
 
// END
 
	, 'object.default');	
}