private String [ ] convertIndsToLabels ( int ... ind ) { String [ ] label = new String [ ind . length ] ; for ( int i = 0 ; i < ind . length ; i ++ ) { if ( ! hasLabel ( ind [ i ] ) ) throw new IllegalArgumentException ( "The index " + ind [ i ] + " does not have a label." ) ; label [ i ] = getLabel ( ind [ i ] ) ; } return label ; }
Converts the indices to the labels . All indices must have an existing label .