A global registry of Testability instances for specific elements.
Testability
class TestabilityRegistry { registerApplication(token: any, testability: Testability): void; unregisterApplication(token: any): void; unregisterAllApplications(): void; getTestability(elem: any): Testability | null; getAllTestabilities(): Testability[]; getAllRootElements(): any[]; findTestabilityInTree(elem: Node, findInAncestors?: boolean): Testability | null;}