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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 Draw(self, dc):
        ''' Draw the tree map on the device context. '''
        self.hot_map = []
        dc.BeginDrawing()
        brush = wx.Brush( self.BackgroundColour  )
        dc.SetBackground( brush )
        dc.Clear()
        if self.model:
            self.max_depth_seen = 0
            font = self.FontForLabels(dc)
            dc.SetFont(font)
            self._em_size_ = dc.GetFullTextExtent( 'm', font )[0]
            w, h = dc.GetSize()
            self.DrawBox( dc, self.model, 0,0,w,h, hot_map = self.hot_map )
        dc.EndDrawing()