'Declare that you are done with this OptionParser.  This cleans up
reference cycles so the OptionParser (and all objects referenced by
it) can be garbage-collected promptly.  After calling destroy(), the
OptionParser is unusable.'

def destroy(self):

    OptionContainer.destroy(self)
    for group in self.option_groups:
        group.destroy()
    del self.option_list
    del self.option_groups
    del self.formatter
