question: public byte [ ] [ ] generateKeys ( final int nkeys ) { if ( nkeys < 0 ) throw new IllegalArgumentException ( ) ; if ( nkeys > maxKeys ) throw new IllegalArgumentException ( ) ; final Set < byte [ ] > set = new TreeSet < byte [ ] > ( BytesUtil . UnsignedByteArrayComparator . INSTANCE ) ; final byte [ ] [ ] keys = new byte [ maxKeys ] [ ] ; int n = 0 ; while ( n < maxKeys ) { final byte [ ] key = new byte [ r . nextInt ( maxKeyLength ) + 1 ] ; r . nextBytes ( key ) ; if ( set . add ( key ) ) { keys [ n ++ ] = key ; } } Arrays . sort ( keys , BytesUtil . UnsignedByteArrayComparator . INSTANCE ) ; for ( int i = nkeys ; i < maxKeys ; i ++ ) { keys [ i ] = null ; } return keys ; }
target:  Generate a set of N random distinct byte[] keys in sorted order using an unsigned byte[] comparison function.