docs: def cmd(send, msg, args):
      """Gets previous nicks.
  
      Syntax: {command} <nick>
  
      """
      if not msg:
          with args['handler'].data_lock:
              users = list(args['handler'].channels[args['target']].users()) if args['target'] != 'private' else [args['nick']]
          msg = choice(users)
      chain = get_chain(args['db'], msg)
      if chain:
          send(" -> ".join(chain))
      else:
          send("%s has never changed their nick." % msg)