Amazon's AWS.NodeHttpClient - no documentation :(

I'm writing a lambda function where I have to write logs to Amazon's ElasticSearch Service. Backend is Node.js. I came across this example on github:

https://github.com/awslabs/amazon-elasticsearch-lambda-samples/blob/master/src/s3_lambda_es.js

Which uses AWS.NodeHttpClient on line 91. The official docs say nothing about it:

http://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS.html

Nor is anything provided about AWS.HttpClient (looks like a sister class of AWS.NodeHttpClient)

So, has anyone used/modified this code successfully before? I really don't want to dig into the node_modules folder hunting for the class description

via Nika Kasradze