question: private StringBuilder debugDumpCandidates ( StringBuilder msg , List < ? extends Itemset > candidates , VectorFieldTypeInformation < BitVector > meta ) { msg . append ( ':' ) ; for ( Itemset itemset : candidates ) { msg . append ( " [" ) ; itemset . appendTo ( msg , meta ) ; msg . append ( ']' ) ; } return msg ; }
target:  Debug method: output all itemsets.