安装elliptic包成功后，进行npm构建，示例代码在本地node环境可以正常运行，但是在微信小程序端运行报错如下： VM6216:1 thirdScriptError Cannot read property 'getBytes' of null TypeError: Cannot read property 'getBytes' of null     at Rand._rand (http://127.0.0.1:56989/appservice/miniprogram_npm/elliptic/miniprogram_npm/brorand/index.js:99:21)     at Rand.generate (http://127.0.0.1:56989/appservice/miniprogram_npm/elliptic/miniprogram_npm/brorand/index.js:94:19)     at rand (http://127.0.0.1:56989/appservice/miniprogram_npm/elliptic/miniprogram_npm/brorand/index.js:84:16)     at EC.genKeyPair (http://127.0.0.1:56989/appservice/miniprogram_npm/elliptic/index.js:2327:37)     at http://127.0.0.1:56989/appservice/pages/index/index.js:18:14     at require (http://127.0.0.1:56989/appservice/__dev__/WAService.js:2:1680701)     at <anonymous>:164:7     at HTMLScriptElement.scriptLoaded (http://127.0.0.1:56989/appservice/appservice?t=1581906450710:4521:21)     at HTMLScriptElement.script.onload (http://127.0.0.1:56989/appservice/appservice?t=1581906450710:4533:20) 如何解决呢，是因为调用了nodejs内置函数吗，所以这个第三方包不能使用？