def add_role(self, role, term, start_date=None, end_date=None,<EOL>**kwargs):
self['<STR_LIT>'].append(dict(role=role, term=term,<EOL>start_date=start_date,<EOL>end_date=end_date, **kwargs))<EOL>
Examples:

leg.add_role('member', term='2009', chamber='upper',
             party='Republican', district='10th')