:calls: `PUT /teams/:id/memberships/:user <http://developer.github.com/v3/orgs/teams>`_
        :param member: :class:`github.Nameduser.NamedUser`
        :param role: string
        :rtype: None

def add_membership(self, member, role=github.GithubObject.NotSet):
        """
        :calls: `PUT /teams/:id/memberships/:user <http://developer.github.com/v3/orgs/teams>`_
        :param member: :class:`github.Nameduser.NamedUser`
        :param role: string
        :rtype: None
        """
        assert isinstance(member, github.NamedUser.NamedUser), member
        assert role is github.GithubObject.NotSet or isinstance(
            role, (str, unicode)), role
        if role is not github.GithubObject.NotSet:
            assert role in ['member', 'maintainer']
            put_parameters = {
                "role": role,
            }
        else:
            put_parameters = {
                "role": "member",
            }
        headers, data = self._requester.requestJsonAndCheck(
            "PUT",
            self.url + "/memberships/" + member._identity,
            input=put_parameters
        )