code: public GetMaterialTotalCountResponse countMaterial(){
          GetMaterialTotalCountResponse response = null;
          String url = BASE_API_URL + "cgi-bin/material/get_materialcount?access_token=#";
          BaseResponse r = executeGet(url);
          String resultJson = isSuccess(r.getErrcode()) ? r.getErrmsg() : r.toJsonString();
          response = JSONUtil.toBean(resultJson, GetMaterialTotalCountResponse.class);
          return response;
      }
docs: 获取已创建永久素材的数量
  @return 永久素材数量结果