$db-> (Ctrl+Space)

$db = DBConnection::getInstance();

$db = new DBConnection();

/**
 * @property int test more magic-property in code hints
 * @method string test_method() more magic-method in code hints
 */
class DBConnection {
	// ...
	public $db_name;
	public $db_user;
	/**
	 * return DBConnection Instance
	 * @return DBConnection 
	 */
	static function getInstance() {
	}
	// ...
}

$db = DBConnection::getInstance();
$db->| // see all of DBConnection 

//or this:
$db_fix = null;
/* @var $db_fix DBConnection */  // tell pdt $db_fix-type
$db_fix->| // see all of DBConnection