@Override
	public final void set( GraphSite site ) {
		if( this.site != null ) {
			for( GraphItem item : children ) {
				this.site.removeItem( item );
			}
			removeFrom( this.site );
		}
		this.site = site;
		if( site != null ) {
			addTo( site );
			for( GraphItem item : children ) {
				site.addItem( item );
			}
		}
	}