Problem: How do you dynamically (at run time) add and remove connections
Solution: An Observer Manager implements the following protocol:
- ``I Want to Observe X'' -- the OM will keep track of who is watching who
- ``Tell Everybody who is Observing Met that I have Changed'' -- the OM
can then tell everybody that an object has changed.
In this way neither the observer nor the observed object need know the
existance of the other.
Intro OOP, Chapter 24, Slide 18