extensions/typescript-language-features/src/languageFeatures/definitions.ts/register
export function register(
	selector: DocumentSelector,
	client: ITypeScriptServiceClient,
) {
	return conditionalRegistration([
		requireSomeCapability(client, ClientCapability.EnhancedSyntax, ClientCapability.Semantic),
	], () => {
		return vscode.languages.registerDefinitionProvider(selector.syntax,
			new TypeScriptDefinitionProvider(client));
	});
}