    "A setter declaration represents the assign block of a [[ValueDeclaration]]."
    shared sealed interface SetterDeclaration
            satisfies NestableDeclaration {

        "The variable value this setter is for."
        shared formal ValueDeclaration variable;

        actual => variable.actual;

        formal => variable.formal;

        default => variable.default;

        shared => variable.shared;

        containingPackage => variable.containingPackage;

        containingModule => variable.containingModule;

        container => variable.container;

        toplevel => variable.toplevel;
    }