public StructureHandle getHandle( SimpleValueHandle valueHandle )
public StructureHandle getHandle( SimpleValueHandle valueHandle, int index )
	public StructureHandle getHandle( SimpleValueHandle valueHandle )	{		if ( valueHandle == null || valueHandle.getListValue( ) == null )			return null;		int posn = valueHandle.getListValue( ).indexOf( this );		if ( posn == -1 )			return null;		return handle( valueHandle, posn );	}