code: func (c *RPCClient) auth(authKey string) error {
  	header := requestHeader{
  		Command: authCommand,
  		Seq:     c.getSeq(),
  	}
  	req := authRequest{
  		AuthKey: authKey,
  	}
  	return c.genericRPC(&header, &req, nil)
  }
docs: // auth is used to perform the initial authentication on connect