'Return an instance of translator.
This method returns an instance of ``default_translator_class`` by default.
Users can replace the translator class with ``app.set_translator()`` API.'

def create_translator(self, *args):

    translator_class = self.app.registry.get_translator_class(self)
    assert translator_class, ('translator    not    found    for    %s' % self.__class__.__name__)
    return translator_class(*args)
