@@ -1,11 +1,20 @@

-export function NoNextMethodError() {}

-NoNextMethodError.prototype = Object.create(Error);

-

-export function NoApplicableMethodError() {}

-NoApplicableMethodError.prototype = Object.create(Error);

+function SubTypeError(name) {

+  const cls = function () {

+    const instance = Error(...arguments);

+    Object.setPrototypeOf(instance, Object.getPrototypeOf(this));

+    Object.defineProperty(instance, "name", {

+      value: name,

+      writable: false,

+    });

+    return instance;

+  };

+  cls.prototype = Object.create(Error);

+  return cls;

+}

-export function NoPrimaryMethodError() {}

-NoPrimaryMethodError.prototype = Object.create(NoApplicableMethodError);

+export const NoNextMethodError = SubTypeError("NoNextMethodError");

+export const NoApplicableMethodError = SubTypeError("NoApplicableMethodError");

+export const NoPrimaryMethodError = SubTypeError("NoPrimaryMethodError");

 const before_qualifier = Symbol.for("before");

 const after_qualifier = Symbol.for("after");