COS 'primitive' types are mutable

From torakiki:
They are cached and they are mutable so this:

        COSInteger cosint = COSInteger.get(10);
        cosint.setValue(50);
        //lets move to a totally unrelated part of my software
        System.out.println(COSInteger.get(10));

prints COSInteger(50) so basically I ask for a 10 and get a 50, isn't it weird (and error prone)? ... or the way around, I call cosint.setValue(50) at some point in the software and that makes it a 50 everywhere I used COSInteger.get(10).

That's of course also true for the other mutable attributes setDirect and setNeedToBeUpdate.