Emit the data changed signal on the model of the treeitem
        if the treeitem has a model.

        :returns: None
        :rtype: None
        :raises: None

def emit_data_changed(self):
        """Emit the data changed signal on the model of the treeitem
        if the treeitem has a model.

        :returns: None
        :rtype: None
        :raises: None
        """
        item = self.get_treeitem()
        m = item.get_model()
        if m:
            start = m.index_of_item(item)
            parent = start.parent()
            end = m.index(start.row(), item.column_count()-1, parent)
            m.dataChanged.emit(start, end)