[Bug] No way to create a `PresentationDefinition`?

[its-danny]

Description

Apologies if I'm missing something, but I can't find a way to create a PresentationDefinition. All the fields are pub(crate), there is no new, and it doesn't impl Default.

I know you can deserialize the JSON of an existing presentation to get it, but I need to make a new presentation.

Hardware Specification

N/A

Steps to Reproduce the Bug

1. Create an empty project.
2. Add dif-presentation-exchange as a dependency.
3. Try to create a PresentationDefinition.

Expected Behaviour

I'd expect a new method or an impl of Default.

Actual Behaviour

That is not the case.

Errors

N/A