presto-main/src/main/java/io/prestosql/operator/PartitionedLookupSource.java/PartitionedLookupSource/isJoinPositionEligible
class PartitionedLookupSource:    @Override
    public boolean isJoinPositionEligible(long currentJoinPosition, int probePosition, Page allProbeChannelsPage)
    {
        int partition = decodePartition(currentJoinPosition);
        long joinPosition = decodeJoinPosition(currentJoinPosition);
        LookupSource lookupSource = lookupSources[partition];
        return lookupSource.isJoinPositionEligible(joinPosition, probePosition, allProbeChannelsPage);
    }