code: @Override
      public java.util.concurrent.Future<ListAccessKeysResult> listAccessKeysAsync(
              com.amazonaws.handlers.AsyncHandler<ListAccessKeysRequest, ListAccessKeysResult> asyncHandler) {
  
          return listAccessKeysAsync(new ListAccessKeysRequest(), asyncHandler);
      }
docs: Simplified method form for invoking the ListAccessKeys operation with an AsyncHandler.
  
  @see #listAccessKeysAsync(ListAccessKeysRequest, com.amazonaws.handlers.AsyncHandler)