module M {
    export interface I {
	z;
    }

    export class C {
	public x=0;
	f(x:I) {
	    x.e;  // e not found
	    x.z;  // ok 
	}
    constructor() {
	({z:10,f:this.f}).f(<I>({}));
    }
    }
}

class C {
    f(x: number) {
    }
}