Hey guys. I am trying to create a unit test for one of my VC.

I would like to test a function within that VC so here is what I wrote:

 func testGetFollowersFunction() {
        // Arrange
        let sut     = FollowersListVC()
        sut.user    = User(login:       "jmgawecki",
                           avatarUrl:   "",
                           name:        "Jakub",
                           location:    "Warsaw",
                           bio:         "Bio",
                           publicRepos: 19,
                           publicGists: 10,
                           htmlUrl:     "",
                           followers:   10,
                           following:   10,
                           createdAt:   "Test")

        // Act
        sut.loadViewIfNeeded()
        sut.getFollowers(page: 1, on: sut.user.login)

        // assert
        XCTAssertEqual(sut.followers.count, 1)   
    }

Function that I am trying to test looks like this:

func getFollowers(page: Int, on username: String) {
        showLoadingView()
        NetworkManager.shared.getFollowers(username: username, page: page) { [weak self] (result) in
            guard let self = self else { return }
            self.dismissLoadingView()

            switch result {
            case .success(let followers):
                if followers.count < 100 { self.hasMoreFollowers.toggle() }
                self.followers.append(contentsOf: followers)
                self.updateData(on: self.followers)
                if self.followers.isEmpty {
                    DispatchQueue.main.async { self.showEmptyStateView(with: "Looks like that user has no followers. Go follow them!", in: self.view) }
                }

            case .failure(let error):
                self.presentGFAlerOnMainThred(title: "Ops", message: error.rawValue, button: "Ok")
            }
        }
    }

That test will not work. XCTAssert will happen before set.getFollowers() will execute. I need to put Expectation and fulfill somewhere in between but I am not sure how to do it. Any suggestions? Thanks!