Type inference contains error suspected to be caused by proxy about n4js HOT 1 CLOSED

export public class C {
	b : B;
	d = new D();
	g = (this.b = this.d, ""); // Error: any is not a subtype of B.
}

abstract class B {}

class D extends B {
	protected c: C;
	f = this.c.g; // removing this line solves the error
}