Get a copy of PDDocument ?

[Kevin Ternes]

In PDFBox 1.8, what is the most efficient way to get a complete copy of an 
existing PDDocument?
Is this:
                PDDocument targetPDDocument = new PDDocument();
                PDFCloneUtility cloneUtility = new 
PDFCloneUtility(targetPDDocument);
                cloneUtility.cloneForNewDocument(sourcePDDocument);
Better than this?:
                PDDocument targetPDDocument = sourcePDDocument.clone();

Also, what is the most efficient way in PDFBox 2?