extensions/typescript-language-features/src/utils/dependentRegistration.ts/ConditionalRegistration/constructor
class ConditionalRegistration:	public constructor(
		private readonly conditions: readonly Condition[],
		private readonly doRegister: () => vscode.Disposable
	) {
		for (const condition of conditions) {
			condition.onDidChange(() => this.update());
		}
		this.update();
	}