code: func findRequestedNodePort(port int, servicePorts []api.ServicePort) int {
  	for i := range servicePorts {
  		servicePort := servicePorts[i]
  		if port == int(servicePort.Port) && servicePort.NodePort != 0 {
  			return int(servicePort.NodePort)
  		}
  	}
  	return 0
  }
docs: // Loop through the service ports list, find one with the same port number and
  // NodePort specified, return this NodePort otherwise return 0.