trait C { val a: Any } fun box(): String { val l = object : C { override val a: Any { a = {} } } val javaClass = l.a.javaClass val enclosingMethod = javaClass.getEnclosingConstructor()!!.getName() if (!enclosingMethod.startsWith("_DefaultPackage\$") || !enclosingMethod.endsWith("\$box\$l\$1")) return "ctor: $enclosingMethod" val enclosingClass = javaClass.getEnclosingClass()!!.getName() if (!enclosingClass.startsWith("_DefaultPackage\$") || !enclosingClass.endsWith("\$box\$l\$1")) return "enclosing class: $enclosingClass" if (enclosingMethod != enclosingClass) return "$enclosingClass != $enclosingMethod" val declaringClass = javaClass.getDeclaringClass() if (declaringClass != null) return "anonymous function has a declaring class: $declaringClass" return "OK" }