presto-main/src/main/java/io/prestosql/execution/ScheduledSplit.java/ScheduledSplit/toString
class ScheduledSplit:    @Override
    public String toString()
    {
        return toStringHelper(this)
                .add("sequenceId", sequenceId)
                .add("planNodeId", planNodeId)
                .add("split", split)
                .toString();
    }