Verifying async logic

[DesmanLead]

It's a common use-case to verify that the method will be called at some moment in the future in a given timeout. It's possible to implement this using Perform, but another version of Verify (e.g. Expect?) would be really handy. So the API design might be as follows:

    override func setUp() {
        super.setUp()

        interactor = MyInteractor()
        interactor.service = mockService
    }

    func testThatInteractorHandlesRefresh() async throws {
        // given
        Given(mockService, .obtainData(...))

        // when
        await interactor.refresh() // calls obtainData asynchronously inside

        // then
        await Expect(mockService, .obtainData(...)) // default timeout
        await Expect(mockService, .obtainData(...), timeout: .seconds(1))
    }

What do you think? It doesn't look hard to implement, so you can just point the right spot to add this.