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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 on_lstUnits_itemSelectionChanged(self):
 """Update unit description label and field widgets. .. note:: This is an automatic Qt slot executed when the unit selection changes. """

        self.clear_further_steps()
        # Set widgets
        unit = self.selected_unit()
        # Exit if no selection
        if not unit:
            return
        self.lblDescribeUnit.setText(unit['description'])
        # Enable the next button
        self.parent.pbnNext.setEnabled(True)