@Override
  public Expression visitTernaryExpression(TernaryExpression ternaryExpression, C context) {
    List<Expression> childResults = getResultsFromChild(ternaryExpression, context);
    return reconstructTernaryExpression(
        ternaryExpression, childResults.get(0), childResults.get(1), childResults.get(2));
  }
Collect result from child, then reconstruct. For example, two child each give me 1 result, I
should use them to reconstruct 1 new result to upper level.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/expression/visitor/ReconstructVisitor.java