private HashMap<String,DBIDs> singleAssignment(Relation<?> data){
  HashMap<String,DBIDs> labelMap=new HashMap<>();
  for (DBIDIter iditer=data.iterDBIDs(); iditer.valid(); iditer.advance()) {
    final Object val=data.get(iditer);
    String label=(val != null) ? val.toString() : null;
    assign(labelMap,label,iditer);
  }
  return labelMap;
}

private HashMap < String , DBIDs > singleAssignment ( Relation < ? > data ) { HashMap < String , DBIDs > labelMap = new HashMap < > ( ) ; for ( DBIDIter iditer = data . iterDBIDs ( ) ; iditer . valid ( ) ; iditer . advance ( ) ) { final Object val = data . get ( iditer ) ; String label = ( val != null ) ? val . toString ( ) : null ; assign ( labelMap , label , iditer ) ; } return labelMap ; }
assigns the objects of the database to single clusters according to their labels .
