HttpClient that has been assigned or has been used by this object. The life cycle might not be or might
be tied to this object, depending on whether HttpClient was passed to or created by this object
Assign an HttpClient that this object should use. The life cycle of the given HttpClient is
independent of this object. Closing or shutting down this object does not have any impact on the given client.
Callers must ensure that the given client is properly closed elsewhere.