Definition of an interface for the thread-safe initialization of objects.

The idea behind this interface is to provide access to an object in a thread-safe manner. A ConcurrentInitializer can be passed to multiple threads which can all access the object produced by the initializer. Through the get() method the object can be queried.

Concrete implementations of this interface will use different strategies for the creation of the managed object, e.g. lazy initialization or initialization in a background thread. This is completely transparent to client code, so it is possible to change the initialization strategy without affecting clients.