def addoption(self, *optnames, **attrs):
conflict = set(optnames).intersection(<EOL>name for opt in self.options for name in opt.names()<EOL>)<EOL>if conflict:<EOL><INDENT>raise ValueError("<STR_LIT>" % conflict)<EOL><DEDENT>option = Argument(*optnames, **attrs)<EOL>self._addoption_instance(option, shortupper=False)<EOL>
add an option to this group.

        if a shortened version of a long option is specified it will
        be suppressed in the help. addoption('--twowords', '--two-words')
        results in help showing '--two-words' only, but --twowords gets
        accepted **and** the automatic destination is in args.twowords