code: @MustBeLocked (ELockType.WRITE)
    protected final void internalMarkItemDeleted (@Nonnull final IMPLTYPE aItem)
    {
      internalMarkItemDeleted (aItem, true);
    }
docs: Mark an item as "deleted" without actually deleting it from the map. This
  method only triggers the update action but does not alter the item. Must
  only be invoked inside a write-lock.
  
  @param aItem
  The item that was marked as "deleted"