_internal->_decorator_func : Decoration func around _internal->_py_call_back to deal with returned values of _internal->_py_call_back
+################# user GIL management in AdaoExchangeLayer
+class AdaoExchangeLayer has been developped to be launched from any thread.
+
+AdaoExchangeLayer manage the GIL (using AutoGIL) in its implementation.
+
+Consequence the AdaoExchangeLayer instance should NOT be surrounded by GIL protection.
+
+############## user GIL management in AdaoModel::MainModel
+
+The custom MainModel overloading should be GIL protected by the user.
