content: function TestSuite__StoreFacade_subscribeOnce() as Object
    ts = StoreFacadeTestSuite()
    ts.name = "StoreFacade_subscribeOnce"
  
    it("should add 1 subscriber", function (_ts)
      ' Given
      expectedResult = 1
      store = StoreFacade()
  
      ' When
      store.subscribeOnce("title", subscriber)
  
      ' Then
      return expect(store._subscriptions.count()).toBe(1)
    end function)
  
    it("should add 2 subscribers", function (_ts)
      ' Given
      expectedResult = 2
      store = StoreFacade()
  
      ' When
      store.subscribeOnce("title", subscriber)
      store.subscribeOnce("test", otherSubscriber)
  
      ' Then
      return expect(store._subscriptions.count()).toBe(2)
    end function)
  
    it("should call callback only once", function (_ts)
      ' Given
      store = StoreFacade()
  
      ' When
      store.subscribeOnce("title", subscriber)
      store.set("title", "someTitle")
      store.set("title", Invalid)
  
      ' Then
      return expect(m.__spy.subscriber.calledTimes).toBe(1)
    end function)
  
    it("should call callback with the given context when it is provided", function (_ts)
      ' Given
      context = { __spy: { contextSubscriber: { calledTimes: 0 } } }
      store = StoreFacade()
  
      ' When
      store.subscribeOnce("title", contextSubscriber, context)
      store.set("title", "someTitle")
  
      ' Then
      return expect(context.__spy.contextSubscriber.calledTimes).toBe(1)
    end function)
  
    return ts
  end function
  