@Override
  public Analysis visitShowCurrentTimestamp(
      ShowCurrentTimestampStatement showCurrentTimestampStatement, MPPQueryContext context) {
    Analysis analysis = new Analysis();
    analysis.setRealStatement(showCurrentTimestampStatement);
    analysis.setFinishQueryAfterAnalyze(true);
    analysis.setRespDatasetHeader(DatasetHeaderFactory.getShowCurrentTimestampHeader());
    return analysis;
  }
@param pathList the paths you want to check
@param schemaTree the given schema tree
@return if all paths you give can be found in schema tree, return a pair of view paths and
    null; else return view paths and the non-exist path.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/analyze/AnalyzeVisitor.java