init method
初始化方法,传入对应的 key 和 secret。 https://help.aliyun.com/document_detail/90998.html#title-jfj-1c5-iau
Implementation
Future<void> init(String appKey, String accessKeyId, String accessKeySecret) {
_accessKeyId = accessKeyId;
_accessKeySecret = accessKeySecret;
return _channel.invokeMethod<void>(
_METHOD_INIT,
<String, dynamic>{'appKey': appKey},
);
}