def _showtraceback(self, etype, evalue, stb):
        """Actually show a traceback.

        Subclasses may override this method to put the traceback on a different
        place, like a side channel.
        """
        print >> io.stdout, self.InteractiveTB.stb2text(stb)
Actually show a traceback.

        Subclasses may override this method to put the traceback on a different
        place, like a side channel.