presto-main/src/main/java/io/prestosql/operator/StageExecutionDescriptor.java/StageExecutionDescriptor/getJsonSerializableGroupedExecutionScanNodes
class StageExecutionDescriptor:    @JsonProperty("groupedExecutionScanNodes")
    public Set<PlanNodeId> getJsonSerializableGroupedExecutionScanNodes()
    {
        return groupedExecutionScanNodes;
    }