Translate the following English sentence to French:
"This, of course, presupposes an agreement, which has not been concluded since the multi-racial constitution of 1997, which was seemingly approved by everyone at the time but which cannot, however, be applied in practice."
Mais naturellement, cela suppose un accord qui n'existe plus depuis la constitution multiraciale de 1997, qui a été approuvée par tout le monde à l'époque mais qui ne peut être appliquée.