<PackageReference Include="Microsoft.AspNet.WebApi.Client" Version="4.0.20710" />

IContentNegotiator

public interface IContentNegotiator
Performs content negotiation. This is the process of selecting a response writer (formatter) in compliance with header values in the request.

Performs content negotiating by selecting the most appropriate MediaTypeFormatter out of the passed in formatters for the given request that can serialize an object of the given type.