Check if my codeigniter 4 runs in multilingual mode.

Hi, How do I know if CI4 is running in multilingual mode?
in other words how to know if segment 1 of url presents the key of the language not another variable?
because the methode 

PHP Code:

$this->request->getLocale() 


always returns the a value ...
if no language key founded it return the default value of:

PHP Code:

$defaultLocale 


In this case, nothing guarantees me that the returned value corresponds to a key of a language, controller or if the site works in multilungue mode or not.
I think even if I use 

PHP Code:

$this->request->getLocale() in_array( this-> request-> config-> supportedLocales)... 


that does not give a guarantee!

Please How to be sure of my mode?

Thank you all