If you want to set up a dependent class, your class must be visible to clients. A dependent
class object is, by definition, not directly managed by clients, however. Instead, clients can only
instantiate and manipulate dependent classes through externally created classes (see the following
sections).
For dependent classes, you will set the Class Instancing property to PublicNotCreatable. This
signifies that an object of this class is visible to a client, but that the client can't create
such an object directly.
