@Nullable public <P> P getPresenter(@NonNull String viewId) {
    PresenterHolder holder = presenterMap.get(viewId);
    return holder == null ? null : (P) holder.presenter;
  }
@ Nullable public < P > P getPresenter ( @ NonNull String viewId ) { PresenterHolder holder = presenterMap . get ( viewId ) ; return holder == null ? null : ( P ) holder . presenter ; }
Get the Presenter for a given {@link MvpView} if exists or <code>null</code>

@param viewId The mosby internal view id
@param <P> The type tof the {@link MvpPresenter}
@return The Presenter for the given view id or <code>null</code>