Dependency injection with IObservable

Just when I started working on my little toolbox I read this series on dependency injection for events which was great inspiration.

When I started working on the PassThruStream I liked the way I could make the pass thru notification points as IObservables since I essentially needed an interface with the same behavior as IObservables. I since the stream should not need to be in a situation where observers are coming and going it was a great match for the pattern used in the finale of the blog series I had read.