code: public final void setServicePid(String servicePid) {
          synchronized (lock) {
              if (servicePid == null) {
                  serviceProperties.remove(SERVICE_PID);
              } else {
                  serviceProperties.put(SERVICE_PID, servicePid);
              }
  
              if (serviceRegistration != null) {
                  serviceRegistration.setProperties(serviceProperties);
              }
          }
      }
docs: Sets the service pid of this {@code BundleClassResolverHelper} instance. This is useful if this class resolver
  needs to be wired to multiple pax-wicket applications.
  
  @param servicePid a {@link java.lang.String} object.