code: func (sp *serverPeer) OnFeeFilter(_ *peer.Peer, msg *wire.MsgFeeFilter) {
  	// Check that the passed minimum fee is a valid amount.
  	if msg.MinFee < 0 || msg.MinFee > btcutil.MaxSatoshi {
  		peerLog.Debugf("Peer %v sent an invalid feefilter '%v' -- "+
  			"disconnecting", sp, btcutil.Amount(msg.MinFee))
  		sp.Disconnect()
  		return
  	}
  
  	atomic.StoreInt64(&sp.feeFilter, msg.MinFee)
  }
docs: // OnFeeFilter is invoked when a peer receives a feefilter bitcoin message and
  // is used by remote peers to request that no transactions which have a fee rate
  // lower than provided value are inventoried to them.  The peer will be
  // disconnected if an invalid fee filter value is provided.