(self)
This method should be implemented by all subclasses of CommCareMobileContactMixin,
        and must return the preferred language code of the contact. For example, "en".
This method should be implemented by all subclasses of CommCareMobileContactMixin,
        and must return the preferred language code of the contact. For example, "en".
This method should be implemented by all subclasses of CommCareMobileContactMixin and must return the preferred language code of the contact . For example en .
def get_language_code(self):
        """
        This method should be implemented by all subclasses of CommCareMobileContactMixin,
        and must return the preferred language code of the contact. For example, "en".
        """
        raise NotImplementedError("Subclasses of CommCareMobileContactMixin must implement method get_language_code().")
def get_language_code ( self ) : raise NotImplementedError ( "Subclasses of CommCareMobileContactMixin must implement method get_language_code()." )