Method constructor

packages/core/test/acceptance/di_spec.ts:1080–1083

(
            @Optional() readonly dirA: DirA,
            @Optional() readonly dirB: DirB,
          )

        })
        class Child {
          constructor(
            @Optional() readonly dirA: DirA,
            @Optional() readonly dirB: DirB,
          ) {}
        }
        @Component({
          selector: 'projector',