Mock implementation of URL state.
class MockPlatformLocation implements PlatformLocation { readonly hostname: string; readonly protocol: string; readonly port: string; readonly pathname: string; readonly search: string; readonly hash: string; readonly state: unknown; getBaseHrefFromDOM(): string; onPopState(fn: LocationChangeListener): VoidFunction; onHashChange(fn: LocationChangeListener): VoidFunction; readonly href: string; readonly url: string; replaceState(state: any, title: string, newUrl: string): void; pushState(state: any, title: string, newUrl: string): void; forward(): void; back(): void; historyGo(relativePosition?: number): void; getState(): unknown;}