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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_widget__configure_event(self, widget, event):
        '''
        Called when size of drawing area changes.
        '''
        if event.x < 0 and event.y < 0:
            # Widget has not been allocated a size yet, so do nothing.
            return
        self.resize(event.width, event.height)