@Override
  protected Properties getNonBlockingRouterProperties(String routerDataCenter) {
    Properties properties =
        super.getNonBlockingRouterProperties(routerDataCenter, PUT_REQUEST_PARALLELISM, DELETE_REQUEST_PARALLELISM);
    properties.setProperty("router.operation.controller", "com.github.ambry.router.QuotaAwareOperationController");

    return properties;
  }
Constructs and returns a VerifiableProperties instance with the defaults required for instantiating
the {@link QuotaAwareOperationController}.
@return the created VerifiableProperties instance.
ambry-router/src/test/java/com/github/ambry/router/NonBlockingRouterTest.java