presto-main/src/main/java/io/prestosql/execution/scheduler/PhasedExecutionSchedule.java/PhasedExecutionSchedule/hasSourceDistributedStage
class PhasedExecutionSchedule:    private static boolean hasSourceDistributedStage(Set<SqlStageExecution> phase)
    {
        return phase.stream().anyMatch(stage -> !stage.getFragment().getPartitionedSources().isEmpty());
    }