code: function (source, target, res) {
          if (!module.exports.operations.canDiff || !module.exports.operations.diff) {
              log.warn('Difference operation not implemented by application');
              Utils.sendMessage(res, HttpStatus.NOT_IMPLEMENTED, JSON.stringify({ error: 'operation not implemented' }));
          } else if (Utils.isNullOrEmpty(target)) {
              log.error('Target state not provided');
              Utils.sendMessage(res, HttpStatus.BAD_REQUEST, JSON.stringify({ error: 'invalid states' }));
          } else if (!module.exports.operations.canDiff(source, target)) {
              log.error('Unable to get difference from source:', source, 'to target:', target);
              Utils.sendMessage(res, HttpStatus.BAD_REQUEST, JSON.stringify({ error: 'invalid states' }));
          } else {
              const result = module.exports.operations.diff(source, target);
              log.debug('Successfully computed difference', result, 'from source:', source, 'to target:', target);
              Utils.sendMessage(res, HttpStatus.OK, JSON.stringify(result));
          }
      }
docs: Internal utility function to calculate difference between two states