question: private List < Datum > sampleNbestList ( int sourceId , Sequence < IString > source , SentenceLevelMetric < IString , String > scoreMetric , List < RichTranslation < IString , String > > translations , List < Sequence < IString > > references ) { int [ ] sourceIds = new int [ 1 ] ; sourceIds [ 0 ] = sourceId ; List < Sequence < IString > > sources = new ArrayList < > ( 1 ) ; sources . add ( source ) ; List < List < RichTranslation < IString , String > > > translationList = new ArrayList < List < RichTranslation < IString , String > > > ( 1 ) ; translationList . add ( translations ) ; List < List < Sequence < IString > > > referenceList = new ArrayList < List < Sequence < IString > > > ( 1 ) ; referenceList . add ( references ) ; return sampleNbestLists ( sourceIds , sources , scoreMetric , translationList , referenceList ) ; }
target:  Select PRO samples from a single instance.