export processors getter in QueryPlanStep

Author: liuneng1994

src/Processors/QueryPlan/AggregatingStep.h

@@ -76,6 +76,11 @@ class AggregatingStep : public ITransformingStep
     /// Argument input_stream would be the second input (from projection).
     std::unique_ptr<AggregatingProjectionStep> convertToAggregatingProjection(const DataStream & input_stream) const;
 
+    const Processors & getProcessors() const override
+    {
+        return aggregating;
+    }
+
 private:
     void updateOutputStream() override;
 

src/Processors/QueryPlan/IQueryPlanStep.h

@@ -107,6 +107,11 @@ class IQueryPlanStep
     /// Append extra processors for this step.
     void appendExtraProcessors(const Processors & extra_processors);
 
+    virtual const Processors & getProcessors() const
+    {
+        return processors;
+    }
+
 protected:
     DataStreams input_streams;
     std::optional<DataStream> output_stream;