Downgrade Method

[pdl]

Specify and write methods for downgrading/inspecting Test::Proto::* objects.

• Test::Proto::Test objects should be able to overload the string function.
• Test::Proto::Base objects should be able to overload the string function.
• Test::Proto::Series objects should be able to overload the string function.
• Test::Proto::Test objects should allow their parameters to be inspectable and ideally modifiable.
• Maybe even some way of reducing an upgraded primitive to the original primitive!?