pdfbox git merge example. Where the final merged file is stored?

I want to use the pdfbox library for java to merge thousands of small pdf files. Looking for an example I found one on the pdfbox site and specifically in the examples it has(PDFMergerExample).
But where the final merged file is saved?

>Solution :

It’s just a class, not a complete sample…
The entry method returns an InputStream, from there you can read the result and store ist to e.g. a file.

public InputStream merge(final List<RandomAccessRead> sources) throws IOException

https://www.baeldung.com/convert-input-stream-to-a-file