apollo-portal/src/main/java/com/ctrip/framework/apollo/openapi/service/ConsumerService.java/ConsumerService/assignNamespaceRoleToConsumer
class ConsumerService:  public List<ConsumerRole> assignNamespaceRoleToConsumer(String token, String appId, String namespaceName) {
    return assignNamespaceRoleToConsumer(token, appId, namespaceName, null);
  }