The I18n instance this registry belongs to.
Registers a new missing translation strategy. This is how messages are defined when a translation cannot be found.
The follow example registers a strategy that always return the phrase "Oops! Missing translation.".
The strategy name.
A function that returns a string the result of a missing translation scope.
The registry of missing-translation strategies. Each I18n instance exposes one as
i18n.missingTranslation; it decides what is rendered (or thrown) when a translation cannot be found, based on the instance'smissingBehavior.