Adding Channel Parameter to a request

[Greg Banister]

It appears there may have been an initial effort to add the channel parameter to a request? If so, was this just a feature that was never finished or is there some other way to get the _channelId field populated?
https://github.com/ericnewton76/gmaps-api-net/blob/master/src/Google.Maps/GoogleSigned.cs#L138-L141

Ideally, I'd like to be able to specify a channel at the request level.