@Override
  public Expression visitTimeSeriesOperand(
      TimeSeriesOperand predicate, Map<String, IMeasurementSchema> context) {
    PartialPath measurementPath = predicate.getPath();
    if (context.containsKey(measurementPath.getMeasurement())) {
      return predicate;
    } else {
      return new NullOperand();
    }
  }
This class is only used for align by device query with template and value filter.

<p>The function of this class is used to remove timeseries which is not in the template.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/expression/visitor/TemplatedConcatRemoveUnExistentMeasurementVisitor.java