apollo-client/src/main/java/com/ctrip/framework/apollo/util/http/DefaultHttpClient.java/DefaultHttpClient/doGet
class DefaultHttpClient:  @Override
  public <T> HttpResponse<T> doGet(HttpRequest httpRequest, final Class<T> responseType) {
    Function<String, T> convertResponse = new Function<String, T>() {
      @Override
      public T apply(String input) {
        return GSON.fromJson(input, responseType);
      }
    };

    return doGetWithSerializeFunction(httpRequest, convertResponse);
  }