Immutable collection, foreach method and mutation

[Baptouuuu]

Hi,

I have a collection class that has the method foreach(callable(T): void): void and I would like to declare the class as immutable since there's never an internal mutation and it never performs an external mutation itself. In the case of the foreach method it's the callable that must perform mutations.

My problem is that if I add @psalm-immutable psalm will tell me that the foreach method does nothing since it returns nothing and doesn't perform any mutation itself.

Is there a way to declare the class immutable and tell psalm that the callable passed to foreach will perform mutation ?