'Let each of the plugins add its own command line arguments, which
may or may not be displayed as help topics.'

def add_plugin_args(self, plugins):

    for (name, plugin_ep) in six.iteritems(plugins):
        parser_or_group = self.add_group(name, description=plugin_ep.long_description)
        plugin_ep.plugin_cls.inject_parser_options(parser_or_group, name)
