private UnorderedPixelsParallelGenerator(ImageOptions options) : base(options) { }
private OrderedRowsParallelGenerator(ImageOptions options) : base(options) { }
private UnorderedParallelRangeGenerator(ImageOptions options) : base(options) { }
protected MandelbrotGenerator(ImageOptions options) { this.options = options; }
private SingleThreadedGenerator(ImageOptions options) : base(options) { }