def METHOD_NAME(self, pen, brush):
    # pen, brush are from ginga.vec
    self.pen = self.cr.get_pen(pen.color, alpha=pen.alpha,
                               linewidth=pen.linewidth)
    if brush is None:
        self.brush = None
    else:
        self.brush = self.cr.get_brush(brush.color, alpha=brush.alpha)