code: ContinuableFuture<PutItemResult> putItem(final String tableName, final Object entity) {
          return asyncExecutor.execute(new Callable<PutItemResult>() {
              @Override
              public PutItemResult call() throws Exception {
                  return dbExecutor.putItem(tableName, entity);
              }
          });
      }
docs: And it may cause error because the "Object" is ambiguous to any type.