inner/nested

http://stackoverflow.com/questions/804453/using-inner-classes-in-c-sharp and http://stackoverflow.com/questions/454218/private-inner-classes-in-c-sharp-why-arent-they-used-more-often discuss how to approach inner/nested classes. These are a way to ensure a one-off helper class, for example an enum, is only used by the only class that needs it. This is pretty ghetto and breaks with a good convention of having one file for every one class (save for perhaps having editable partials separate from not-to-be-fucked-with code-generated classes) where the file has the save name as the class it holds.