AvlNode<E> header = new AvlNode<>();
    Serialization.getFieldSetter(TreeMultiset.class, "header").set(this, header);
    successor(header, header);
    Serialization.populateMultiset(this, stream);
  }

  @GwtIncompatible // not needed in emulated source
  @J2ktIncompatible
  private static final long serialVersionUID = 1;

    AvlNode<E> header = new AvlNode<>();
    Serialization.getFieldSetter(TreeMultiset.class, "header").set(this, header);
    successor(header, header);
    Serialization.populateMultiset(this, stream);
  }

  @GwtIncompatible // not needed in emulated source
  @J2ktIncompatible
  private static final long serialVersionUID = 1;