apple_current_locale_identifier(-Identifier)Unify Identifier with the value for CFLocaleGetIdentifier() 
of the Apple current locale. The Identifier is an atom that 
consists of the primary language identifier, e.g., en for 
English followed by an underscore and an identifier for the Region 
in the MacOS
Language & Region preferences. For example, with the 
primary language set to “English (UK)” and the Region 
to “United Kingdom” we get en_GB. This relates 
to the locale identifier
en_GB.UTF-8. Unfortunately it is not that simple. For 
example, we can combine the primary language “English (UK)” with 
the
Region “Netherlands” to end up with en_NL 
which is not a valid MacOS locale.