docs: protected void findAllExpressionsOfClass(Class< ? extends AbstractExpression> aeClass,
              Set<AbstractExpression> collected) {
          // Check the inlined plan nodes
          for (AbstractPlanNode inlineNode: getInlinePlanNodes().values()) {
              // For inline node we MUST go recursive to its children!!!!!
              inlineNode.findAllExpressionsOfClass(aeClass, collected);
          }
  
          // and the output column expressions if there were no projection
          NodeSchema schema = getOutputSchema();
          if (schema != null) {
              schema.addAllSubexpressionsOfClassFromNodeSchema(collected, aeClass);
          }
      }