ViewModelProvider.java

public class ViewModelProvider {
  ...
  private final Factory mFactory;
  private final ViewModelStore mViewModelStore;
  // ① Use ViewModelStoreOwner
  public ViewModelProvider(@NonNull ViewModelStoreOwner owner) {  
    this(owner.getViewModelStore(), owner instanceof HasDefaultViewModelProviderFactory
        ? ((HasDefaultViewModelProviderFactory) owner).getDefaultViewModelProviderFactory()
        : NewInstanceFactory.getInstance());
  }
  // ② Use ViewModelStoreOwner, Factory
  public ViewModelProvider(@NonNull ViewModelStoreOwner owner, @NonNull Factory factory) { 
    this(owner.getViewModelStore(), factory);
  }
  // ③ Use ViewModelStore, Factory
  public ViewModelProvider(@NonNull ViewModelStore store, @NonNull Factory factory) {
    mFactory = factory;
    mViewModelStore = store;
  }
  ...
}