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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 treeWidgetChanged(self):
 """Called when this item is added or removed from a tree."""

        ParameterItem.treeWidgetChanged(self)

        # add all widgets for this item into the tree
        if self.widget is not None:
            tree = self.treeWidget()
            if tree is None:
                return
            tree.setItemWidget(self, 1, self.layoutWidget)
            self.displayLabel.hide()
            self.selected(False)