Thank you @crcrpar for your answer!
You are right its a typo from my side, I will edit it now, sorry for this.
I already read this :
‘the serialized data is bound to the specific classes and the exact directory structure used, so it can break in various ways when used in other projects, or after some serious refactors.’
but did not understand at all… If you have simpler words to explain it I will be very happy to hear it.