def add_to_members(self, member, role=github.GithubObject.NotSet):
assert isinstance(role, (str, unicode)), role<EOL>assert isinstance(member, github.NamedUser.NamedUser), member<EOL>put_parameters = {}<EOL>if role is not github.GithubObject.NotSet:<EOL><INDENT>put_parameters["<STR_LIT>"] = role<EOL><DEDENT>headers, data = self._requester.requestJsonAndCheck(<EOL>"<STR_LIT>",<EOL>self.url + "<STR_LIT>" + member._identity, input=put_parameters<EOL>)<EOL>
:calls: `PUT /orgs/:org/memberships/:user <https://developer.github.com/v3/orgs/members/#add-or-update-organization-membership>`_
:param member: :class:`github.NamedUser.NamedUser`
:param role: string
:rtype: None