Looks up a reference from the widget based on its object name.
        
        :param      name | <str>
                    cls  | <subclass of QtGui.QObject>
        
        :return     <QtGui.QObject> || None

def findReference(self, name, cls=QtGui.QWidget):
        """
        Looks up a reference from the widget based on its object name.
        
        :param      name | <str>
                    cls  | <subclass of QtGui.QObject>
        
        :return     <QtGui.QObject> || None
        """
        ref_widget = self._referenceWidget
        if not ref_widget:
            return None
        
        if ref_widget.objectName() == name:
            return ref_widget
        return ref_widget.findChild(cls, name)