This method needs an argument, an object that represents the application instance.
An application consists of a set of object, however there is a single object, which
is used by the corresponding application container to manage the lifecycle on the
application instance. The lifetime of this object equals the lifetime of
the application instance; therefore, it is suitable to represent the instance.
The returned ApplicationContext
object is singleton for the
specified application instance. Subsequent calls to this method with the same
application instance must return the same context object