what emitLanguageChangedCallback() does? Not documented

[nico23]

In the E-Bike Demo, inside LanguageSelector.cpp (Container) there's the function 

void LanguageSelector::setLanguage(LanguageId selectedLanguage)

where, at the very end, after updating the cache calls the function

emitLanguageChangedCallback();

 Unfortunately, it is not Documented.

I'm seeing the auto-generated Base Function of LanguageSelector has a virtual function

virtual void emitLanguageChangedCallback()
    {
        if (languageChangedCallback && languageChangedCallback->isValid())
        {
            this->languageChangedCallback->execute();
        }
    }

I suppose that it refresh the cache of all the text managed by the translation engine in ToucGFX Designer but, it's just a guess