presto-main/src/main/java/io/prestosql/execution/scheduler/ScheduleResult.java/ScheduleResult/toString
class ScheduleResult:    @Override
    public String toString()
    {
        return toStringHelper(this)
                .add("finished", finished)
                .add("newTasks", newTasks.size())
                .add("blocked", !blocked.isDone())
                .add("splitsScheduled", splitsScheduled)
                .add("blockedReason", blockedReason)
                .toString();
    }