Metaobject supporting object finalization
Warning: this role is part of the Rakudo implementation, and is not a part of the language specification.
This role takes care that
DESTROY submethods are called (if they exist) when an object is garbage-collected.
DESTROY submethods from this class and all its superclasses, and marks the class as needing action on garbage collection.
A metamodel for a kind that implements finalization semantics must call this method at type composition time.
method destroyers( --> List)
Returns a list of all finalization methods.