question: private int compareVdcConfigVersion ( String left , String right ) { if ( left == null && right == null ) { return 0 ; } if ( left == null && right != null ) { return - 1 ; } if ( left != null && right == null ) { return 1 ; } return ( int ) ( Long . parseLong ( left ) - Long . parseLong ( right ) ) ; }
target:  compare vdc config version