@Deprecated
    public DiffReport performDiff(FastBlobStateEngine fromState, FastBlobStateEngine toState, SerializerFactory factory) throws DiffReportGenerationException {
        return performDiff(null, fromState, toState, factory);
    }
@ Deprecated public DiffReport performDiff ( FastBlobStateEngine fromState , FastBlobStateEngine toState , SerializerFactory factory ) throws DiffReportGenerationException { return performDiff ( null , fromState , toState , factory ) ; }
@deprecated instead use the interface provided by {@link DiffOperation}