public void TestForLybrary()
        {
            Library lib = new Library();
            lib.LibAddCodeOpRoot(new AddCodeOpRoot());
            lib.LibAddCodeOpRoot(new SubCodeOpRoot());

            // on test la methode LibIsOpCodeRootExiste
            Assert.That(lib.LibIsCodeOpRootExiste("toto"), Is.False);
            Assert.That(lib.LibIsCodeOpRootExiste("add"), Is.True);

            CodeOpRoot operation = lib.LibFindOpCodeRoot("sub");

            // on test qu'un CodeOpRoot est crée correctement
            Assert.That(operation.Name, Is.EqualTo("sub"));
            Assert.That(operation.GetType(), Is.EqualTo(typeof(SubCodeOpRoot)));
        }