def RenameGroup(r, group, new_name):
    """
    Changes the name of a node group.

    @type group: string
    @param group: Node group name
    @type new_name: string
    @param new_name: New node group name

    @rtype: int
    @return: job id
    """
    body = {'new_name': new_name}
    return r.request('put', '/2/groups/%s/rename' % group, content=body)
