public Expression applyLevels(Expression expression, Analysis analysis) {
    return applyLevels(false, expression, null, analysis);
  }
Only used to check whether one alisa is corresponding to only one column. i.e. Different
columns can't have the same alias.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/analyze/GroupByLevelHelper.java