createSingletonInjectionToken

Creates an injection token/provider pair for a DI token that holds a singleton service.

See DaffSingletonInjectionToken.

const createSingletonInjectionToken: <T = unknown>(desc: [string, { providedIn?: Type<any> | "root" | "platform" | "any"; factory: () => unknown; }?], options?: [string, { providedIn?: Type<any> | "root" | "platform" | "any"; factory: () => unknown; }?]) => DaffSingletonInjectionToken<...>