code: @SuppressWarnings("unchecked")
      protected final <ViewType extends View> ViewType findViewById(@IdRes final int viewId) {
          Condition.INSTANCE.ensureNotNull(currentParentView, "No parent view set",
                  IllegalStateException.class);
          ViewHolder viewHolder = (ViewHolder) currentParentView.getTag();
  
          if (viewHolder == null) {
              viewHolder = new ViewHolder(currentParentView);
              currentParentView.setTag(viewHolder);
          }
  
          return (ViewType) viewHolder.findViewById(viewId);
      }
docs: References the view, which belongs to a specific resource ID by using the view holder
  pattern. The view is implicitly casted to the type of the field it is assigned to.
  
  @param <ViewType>
  The type, the view is implicitly casted to. It must be inherited from the class
  {@link View}
  @param viewId
  The resource ID of the view, which should be referenced, as an {@link Integer} value.
  The ID must be a valid resource ID of the parent view of the view, whose appearance
  is currently customized by the adapter
  @return The view, which belongs to the given resource ID, as an instance of the class {@link
  View} or null, if no view with the given ID is available