Interface to be implemented by any object that wishes to be notified
of the MessageSource (typically the ApplicationContext) that it runs in.
Note that the MessageSource can usually also be passed on as bean
reference (to arbitrary bean properties or constructor arguments), because
it is defined as bean with name "messageSource" in the application context.
Note that the MessageSource can usually also be passed on as bean reference (to arbitrary bean properties or constructor arguments), because it is defined as bean with name "messageSource" in the application context.