message: BaseEventIndexManager: Fix the type hints for the empty promises.
diff: @@ -105,7 +105,7 @@ export default class BaseEventIndexManager {
  * @return {Promise} A promise that will resolve when the event index is
  * initialized.
  */
  - async initEventIndex(): Promise<> {
  + async initEventIndex(): Promise<void> {
  throw new Error("Unimplemented");
  }
  @@ -146,7 +146,7 @@ export default class BaseEventIndexManager {
  * @return {Promise} A promise that will resolve once the queued up events
  * were added to the index.
  */
  - async commitLiveEvents(): Promise<> {
  + async commitLiveEvents(): Promise<void> {
  throw new Error("Unimplemented");
  }
  @@ -197,7 +197,7 @@ export default class BaseEventIndexManager {
  * @return {Promise} A promise that will resolve once the checkpoint has
  * been stored.
  */
  - async addCrawlerCheckpoint(checkpoint: CrawlerCheckpoint): Promise<> {
  + async addCrawlerCheckpoint(checkpoint: CrawlerCheckpoint): Promise<void> {
  throw new Error("Unimplemented");
  }
  @@ -210,7 +210,7 @@ export default class BaseEventIndexManager {
  * @return {Promise} A promise that will resolve once the checkpoint has
  * been removed.
  */
  - async removeCrawlerCheckpoint(checkpoint: CrawlerCheckpoint): Promise<> {
  + async removeCrawlerCheckpoint(checkpoint: CrawlerCheckpoint): Promise<void> {
  throw new Error("Unimplemented");
  }
  @@ -250,7 +250,7 @@ export default class BaseEventIndexManager {
  * @return {Promise} A promise that will resolve once the event index has
  * been closed.
  */
  - async closeEventIndex(): Promise<> {
  + async closeEventIndex(): Promise<void> {
  throw new Error("Unimplemented");
  }
  @@ -260,7 +260,7 @@ export default class BaseEventIndexManager {
  * @return {Promise} A promise that will resolve once the event index has
  * been deleted.
  */
  - async deleteEventIndex(): Promise<> {
  + async deleteEventIndex(): Promise<void> {
  throw new Error("Unimplemented");
  }
  }
  