FakeAPI.swift

struct FakeAPI {
    static let api = API<FakeAPITarget>()
    
    static func allPosts() -> Observable<[Post]> {
        return api.provide(.posts)
    }
}

class PostsDataSource {
    func reloadData() {
        self.state.value = .loading
        
        FakeAPI.allPosts().subscribe { [weak self] (event) in
            switch event {
            case .next(let posts):
                self?.state.value = .loaded(items: posts)
            case .error(let error):
                self?.state.value = .error(error: error)
            default:
                break
            }
         }.disposed(by: disposeBag)
    }
}