请问两个问题：
1.沙箱key是一次性的吗，每次API调用都得重新生成一次，还是说只要生成一次就可以保存下来重复使用呢，
2.生成沙箱key用到的nonce_str和微信各API里面用到的nonce_str有关系吗？
相关文档
- generate Android Signature and Public Key: Mini Program/Development/Extended/Operating Guide/About packaging/Generate Android Signature and Public Key
- I. Generation Android Signature and Public Key: Mini Program/Development/Extended/Operating Guide/About packaging/Generate Android Signature and Public Key
- III. Will Android Signature and public key App Filing platform: Mini Program/Development/Extended/Operating Guide/About packaging/Generate Android Signature and Public Key
- 需要帮助: 小程序/开发/指南/连接硬件能力/需要帮助
- II. Will Android Sign in the WeChat open platform mobile application: Mini Program/Development/Extended/Operating Guide/About packaging/Generate Android Signature and Public Key