How to use generics with Angular CDK's Dialog.open<?????>

I’m trying to figure out what interfaces to put inside the generics section of the open function from Angular’s CDK Dialog. Note that this is not angular material!!

This is what I have figured out so far

const dialogRef = this.dialog.open<IResult, unknown, IInputData>(FooComponent, {
  width: '350px',
  data: { x: 10 } as IInputData
})

dialogRef.closed.subscribe((data: IResult) => { ... }

As you can see I already figured out 2 generics (the first and the last). But it is still unclear what the middle generic should be. So, because generics aren’t mentioned in the documentation I checked out the interface of open which is

open<R = unknown, D = unknown, C = unknown>(component: ComponentType<C>, config?: DialogConfig<D, DialogRef<R, C>>): DialogRef<R, C>;
open<R = unknown, D = unknown, C = unknown>(template: TemplateRef<C>, config?: DialogConfig<D, DialogRef<R, C>>): DialogRef<R, C>;
open<R = unknown, D = unknown, C = unknown>(componentOrTemplateRef: ComponentType<C> | TemplateRef<C>, config?: DialogConfig<D, DialogRef<R, C>>): DialogRef<R, C>;

It is generic D that I’m interested in. Its used in DialogConfig which looks like this

/** Configuration for opening a modal dialog. */
export declare class DialogConfig<D = unknown, R = unknown, C extends BasePortalOutlet = BasePortalOutlet> {
    ...

    /**
     * Providers that will be exposed to the contents of the dialog. Can also
     * be provided as a function in order to generate the providers lazily.
     */
    providers?: StaticProvider[] | ((dialogRef: R, config: DialogConfig<D, R, C>, container: C) => StaticProvider[]);
    /**
     * Component into which the dialog content will be rendered. Defaults to `CdkDialogContainer`.
     * A configuration object can be passed in to customize the providers that will be exposed
     * to the dialog container.
     */
    container?: Type<C> | {
        type: Type<C>;
        providers: (config: DialogConfig<D, R, C>) => StaticProvider[];
    };
 ...

Here is where I’m lost. Any suggestions what D might be?

>Solution :

D is the type of the data being injected into the child component. As per the source:

/** Data being injected into the child component. */
data?: D | null = null;