code: public static void removeAllThreadIdentityServices() {
          threadIdentityServices.clear();
          if (TraceComponent.isAnyTracingEnabled() && tc.isDebugEnabled()) {
              Tr.debug(tc, "All the ThreadIdentityService implementations were removed.");
          }
      }
docs: Remove all the ThreadIdentityService references. This method is called by
  ThreadIdentityManagerConfigurator when the ThreadIdentityService service tracker is closed.