code: public ContactTrackingService getContactTrackingService() {
          if (_contactTrackingService == null) {
              synchronized (CCApi2.class) {
                  if (_contactTrackingService == null) {
                      _contactTrackingService = _retrofit.create(ContactTrackingService.class);
                  }
              }
          }
  
          return _contactTrackingService;
      }
docs: Gets the contact tracking service.
  
  @return the contact tracking service