I think the ambiguity comes from the fact that a manifest, when modelled as a class, es a singleton.

So it really doesn't matter where the methods are; they will work.

If this where modelled properly, a single class which would hold the Package data,

then we would have only one class (Package) and several instances, each with its own variables:

author, comment, creationDate, etc.

So for now, maybe it's irrelevant the distinction. Because where the methods are do not really reflect anything on the reality we are modelling.