Accessing HTTP Headers To Parse Custom Headers From Response

[Gintoki0149]

I am sending requests to S3 for uploading objects and modifying the response form S3 to enrich the response headers with some custom headers. I want to be able to extract these headers in the S3Client for further processing. What is the best way to do this?

1. I have tried using SetHeadersReceivedEventHandler but that doesn't work in cases where the response body is empty.(e.g. in PutObject)
2. I saw that there is an interceptor interface being exposed and an m_interceptors vector being used in AWSClient.cpp. Adding a custom interceptor in the vector should suffice since then I can extract the custom headers in the ModifyBeforeDeserialization function of the interceptor implementation. But I see that the m_interceptors variable is private and there is no setter to modify it nor is there any constructor where I can specify a vector for the same. Currently it is hardcoded to have only a checksum interceptor and a chunking interceptor.
   Would it be possible to add injecting custom interceptors or is there some other way in which we can extract custom headers?