Observer Design Pattern in Golang

Question

I am trying to practice the Observer design pattern in Golang, here is my code. I would be pleased to receive your comments, improvements, etc.

package observer

import (
    "container/list"
    "fmt"
    "math/rand"
)

//interface that receive updates
type Observer interface{
    Update(s *Subject)
}

// interface that manage notifying
type Subject struct{
    observers *list.List
    status int
}

func NewSubject() *Subject {
    //this can be categorized from database etc
    return &Subject{observers:new(list.List)}
}

func (s *Subject) Attach(o Observer){
    s.observers.PushBack(o)
}

func (s *Subject) DeAttach(o Observer){
    for obs := s.observers.Front(); obs != nil; obs = obs.Next() {
        if obs.Value.(Observer) == o {
            s.observers.Remove(obs)
        }
    }
}

func (s *Subject) notify(){
    for obs := s.observers.Front(); obs != nil; obs = obs.Next() {
        observer := obs.Value.(Observer)
        observer.Update(s)
    }
}

// some business logic function to notify
func (s *Subject) ScanData() {

    // just generate random number for status
    // this can be a business logic in real world to calculate or fetch status for a specific source or logic
    s.status = rand.Intn(1000)
    s.notify()
}

//Concrete class A for Observer
type ConcreteNotifierA struct{
}

func NewConcreteNotifierA() *ConcreteNotifierA {
    return &ConcreteNotifierA{
    }
}

func (a *ConcreteNotifierA) Update(s *Subject) {
    if s.status > 500 {
        fmt.Printf("Status is bigger than 500: %v \n", s.status)
    }
}


//Concrete class B for Observer
type ConcreteNotifierB struct{
}

func NewConcreteNotifierB() *ConcreteNotifierB {
    return &ConcreteNotifierB{
    }
}

func (b *ConcreteNotifierB) Update(s *Subject) {
    if s.status < 501 {
        fmt.Printf("Status is less than 500: %v \n", s.status)
    }
}

And here is testing:

subject := observer.NewSubject()
concreteObserverA := observer.NewConcreteNotifierA()
concreteObserverA1 := observer.NewConcreteNotifierA()
concreteObserverB := observer.NewConcreteNotifierB()
concreteObserverB1 := observer.NewConcreteNotifierB()

subject.Attach(concreteObserverA)
subject.Attach(concreteObserverA1)
subject.Attach(concreteObserverB)
subject.Attach(concreteObserverB1)

fmt.Printf("First Scan\n")
subject.ScanData()

subject.DeAttach(concreteObserverB)
subject.DeAttach(concreteObserverA)

fmt.Printf("Second Scan\n")
subject.ScanData()

EDIT: Let's say the goal is on different type of "Status", different type of subscribers will be notified.