struct YourState: ExpandableState {
    
    enum Section: String, CaseIterable {
        case first
        case second
    }

    static var `default`: YourState { 
        return YourState(
            text: "Hello, World!",
            expandableDict: YourState.Section.allCases.map { $0.rawValue }
                .reduce(into: [String: Bool](), { (current: inout [String: Bool], id: String) -> Void in
                    current[id] = false
                }
        ) 
    } 

    var text: String
    var expandableDict: [String: Bool]
}

class YourViewModel: ViewModel<YourState> {
    func showCyanic() {
        self.setState { $0.text = "Hello, Cyanic!" }
    }
}

class YourComponentViewController: SingleSectionCollectionComponentViewController {
    
    private let viewModel: YourViewModel = YourViewModel(initialState: YourState.default)
    
    override var viewModels: [AnyViewModel] {
        return [self.viewModel.asAnyViewModel]
    }
    
    override func buildComponents(_ componentsController: inout ComponentsController) {
        withState(self.viewModel) { (state: YourState) -> Void in
            componentsController.staticTextComponent {
                $0.id = "title"
                $0.text = state.text
            }
            
            componentsController.buttonComponent {
                $0.id = "button"
                $0.onTap = { [weak self]
                    self?.viewModel.showCyanic()
                }
            }
            
            let firstExpandableID: String = YourState.Section.first.rawValue
            
            let yourExpandable = components.expandableComponent { [weak self] in
                guard let s = self else { return }
                $0.id = firstExpandableID
                $0.contentLayout = LabelContentLayout(text: Text.unattributed("Hello, World!"))
                $0.isExpanded = state.expandableDict[firstExpandableID] ?? false
                $0.setExpandableState = self.viewModel.setExpandableState
                $0.backgroundColor = UIColor.lightGray
                $0.height = 55.0
            }
            
            // These ButtonComponents will only show up when yourExpandable is expanded.
            if yourExpandable.isExpanded {
                for number in 1...5 {
                    componentsController.buttonComponent {
                        $0.id = "button\(number)"
                        $0.title = "\(number)"
                        $0.onTap = { [weak self]
                            print("Hello, World from Button \(number)")
                        }
                    }
                }
            }
        }
    }
}