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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def update(self, users=None, groups=None):
 """Add the specified users or groups to this project role. One of ``users`` or ``groups`` must be specified. :param users: a user or users to add to the role :type users: string, list or tuple :param groups: a group or groups to add to the role :type groups: string, list or tuple """


        if users is not None and isinstance(users, string_types):
            users = (users,)
        if groups is not None and isinstance(groups, string_types):
            groups = (groups,)

        data = {
            'id': self.id,
            'categorisedActors': {
                'atlassian-user-role-actor': users,
                'atlassian-group-role-actor': groups}}

        super(Role, self).update(**data)