code: @SuppressWarnings("unchecked")
    public static <T> T create(Class<T> proxyInterface, ClassLoader classLoader) {
      Objects.requireNonNull(proxyInterface, "proxyInterface 不能为null");
      if (!proxyInterface.isInterface()) {
        throw new IllegalArgumentException(proxyInterface.getName() + "不是一个接口");
      }
      if (!proxyInterface.isAnnotationPresent(Rest.class)) {
        throw new IllegalArgumentException(proxyInterface.getName() + "必须添加@Rest注解");
      }
      classLoader = classLoader == null ? Thread.currentThread().getContextClassLoader() : classLoader;
      // 当Thread.currentThread.getContextClassLoader()为null时重新赋值
      classLoader = classLoader == null ? RequestInvoker.class.getClassLoader() : classLoader;
      return (T) Proxy.newProxyInstance(
          classLoader,
          new Class[]{proxyInterface, HttpClientConfig.class},
          new RequestInvoker(proxyInterface));
    }
docs: 创建请求代理
  
  @param proxyInterface 被代理的接口
  @param classLoader 类加载器