def setModelData(self, editor, model, index):
        """Updates the model after changing data in the editor.

        Args:
            editor (QtGui.QComboBox): The current editor for the item. Should be
                a `QtGui.QComboBox` as defined in `createEditor`.
            model (ColumnDtypeModel): The model which holds the displayed data.
            index (QtCore.QModelIndex): The index of the current item of the model.

        """
        model.setData(index, editor.itemText(editor.currentIndex()))