PdfSweep 4.0.1 partial redaction of found string

Question

I've been working on a pdf redaction tool and found this very slick code. It does nearly everything which is needed and so quickly.

The trouble is I need to redact all but the last four or the found string. I have tinkered w/custom cleanup strategy, the autocleanup, etc.. I'm missing something.

What are some options to use the following, and redact only a portion of the found text?

Thanks in advance for your input,

`try (PdfDocument pdf = new PdfDocument(new PdfReader(SRC), new PdfWriter(new_File(SRC, "redact")))) 
{
            final ICleanupStrategy cleanupStrategy = new RegexBasedCleanupStrategy(Pattern.compile("Alice", Pattern.CASE_INSENSITIVE)).setRedactionColor(ColorConstants.PINK);
            PdfCleaner.autoSweepCleanUp(pdf, cleanupStrategy);
}`

I have tinkered w/custom cleanup strategy, the autocleanup, etc.. I'm missing something. I've reviewed documentation here, unable to connect all the dots:

https://api.itextpdf.com/pdfSweep/dotnet/latest/