code: func (p *peer) updateFlowControl(update keyValueMap) {
  	if p.fcServer == nil {
  		return
  	}
  	params := p.fcParams
  	updateParams := false
  	if update.get("flowControl/BL", &params.BufLimit) == nil {
  		updateParams = true
  	}
  	if update.get("flowControl/MRR", &params.MinRecharge) == nil {
  		updateParams = true
  	}
  	if updateParams {
  		p.fcParams = params
  		p.fcServer.UpdateParams(params)
  	}
  	var MRC RequestCostList
  	if update.get("flowControl/MRC", &MRC) == nil {
  		p.fcCosts = MRC.decode()
  	}
  }
docs: // updateFlowControl updates the flow control parameters belonging to the server
  // node if the announced key/value set contains relevant fields