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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 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)