'Transfer the region of the agg buffer defined by bbox to the display.
If bbox is None, the entire buffer is transferred.'

def blit(self, bbox=None):

    if (bbox is None):
        self.bitmap = _convert_agg_to_wx_bitmap(self.get_renderer(), None)
        self.gui_repaint()
        return
    (l, b, w, h) = bbox.bounds
    r = (l + w)
    t = (b + h)
    x = int(l)
    y = int((self.bitmap.GetHeight() - t))
    srcBmp = _convert_agg_to_wx_bitmap(self.get_renderer(), None)
    srcDC = wx.MemoryDC()
    srcDC.SelectObject(srcBmp)
    destDC = wx.MemoryDC()
    destDC.SelectObject(self.bitmap)
    destDC.Blit(x, y, int(w), int(h), srcDC, x, y)
    destDC.SelectObject(wx.NullBitmap)
    srcDC.SelectObject(wx.NullBitmap)
    self.gui_repaint()
