How to let D's one module contains lots of classes.

[AlanThinker via Digitalmars-d]

I notice that lots of GUI library will create a module which have 
the same name as the class to hold a class. such as:
///
module tkd.widget.button;
class Button
///

If one module can have different classes in different files.
It can change to:
///
module tkd.widget;
class Button
///

If someone want port a C# library to D, it will helpful to keep D 
code and C# same. then library user can port there app easily to 
D.