code: func (cm *rpcConnManager) RemoveByID(id int32) error {
  	replyChan := make(chan error)
  	cm.server.query <- removeNodeMsg{
  		cmp:   func(sp *serverPeer) bool { return sp.ID() == id },
  		reply: replyChan,
  	}
  	return <-replyChan
  }
docs: // RemoveByID removes the peer associated with the provided id from the list of
  // persistent peers.  Attempting to remove an id that does not exist will return
  // an error.
  //
  // This function is safe for concurrent access and is part of the
  // rpcserverConnManager interface implementation.