Extending Collector to handle a post-transform

[Tim Peierls]

On Tue, Jun 11, 2013 at 1:44 PM, Tim Peierls <tim at peierls.net> wrote:

> Could Collector<T, R> extend BaseCollector<T, X, R>?
>

Well, no. But there has to be some way to hide the otherwise
client-invisible type parameter.

--tim