code: public static final synchronized KnowledgeRuntimeManager getRuntimeManager(QName serviceDomainName, QName serviceName) {
          if (serviceDomainName == null) {
              serviceDomainName = ROOT_DOMAIN;
          }
          Map<QName, KnowledgeRuntimeManager> reg = REGISTRY.get(serviceDomainName);
          return reg != null ? reg.get(serviceName) : null;
      }
docs: Gets a runtime manager.
  
  @param serviceDomainName the service domain name
  @param serviceName the service name
  @return the runtime manager