extensions/typescript-language-features/src/tsServer/versionProvider.electron.ts/DiskTypeScriptVersionProvider/getApiVersion
class DiskTypeScriptVersionProvider:	private static getApiVersion(serverPath: string): API | undefined {
		const version = DiskTypeScriptVersionProvider.getTypeScriptVersion(serverPath);
		if (version) {
			return version;
		}

		// Allow TS developers to provide custom version
		const tsdkVersion = vscode.workspace.getConfiguration().get<string | undefined>('typescript.tsdk_version', undefined);
		if (tsdkVersion) {
			return API.fromVersionString(tsdkVersion);
		}

		return undefined;
	}