question: private static int lastIndexOf ( Object o , Object [ ] elements , int index ) { if ( o == null ) { for ( int i = index ; i >= 0 ; i -- ) if ( elements [ i ] == null ) return i ; } else { for ( int i = index ; i >= 0 ; i -- ) if ( o . equals ( elements [ i ] ) ) return i ; } return - 1 ; }
target:  static version of lastIndexOf.