protected List<Callable<T>> getRequests() {
    return requests;
  }
Do the requests which have been added, and then comparing their return values. If all the
values are equal, one value will be returned. Otherwise an {@link SQLException} will be thrown.

@return the return value of one request, as all requests return the same one.
@throws SQLException if any error happens during requesting.
@throws InconsistentDataException if the return values of requests are not equal.
integration-test/src/main/java/org/apache/iotdb/itbase/runtime/RequestDelegate.java