question: private void copyScheduleIntoFrontier ( final int minCapacity , final Iterator < Value > itr ) { backing . ensureCapacity ( minCapacity ) ; final Value [ ] a = backing . array ( ) ; int nvertices = 0 ; while ( itr . hasNext ( ) ) { final Value v = itr . next ( ) ; a [ nvertices ++ ] = v ; } for ( int i = nvertices ; i < a . length ; i ++ ) { if ( a [ i ] == null ) break ; a [ i ] = null ; } this . vertices = backing . slice ( 0 , nvertices ) ; }
target:  Copy the data from the iterator into the backing array and update the slice which provides our exposed view of the backing array.