public void AddItemArea()
        {
            Project project = Project.Empty();

            Assert.DoesNotThrow(() => project.AddItem(new Equipment("Area 1")));
        }
        public void AddItemWorkCentre()
        {
            Project project = Project.Empty();

            Assert.DoesNotThrow(() => project.AddItem(new Equipment("WorkCentre")));
        }
        public void AddItemNull()
        {
            Project project = Project.Empty();

            Assert.Throws <ArgumentNullException>(() => project.AddItem(null));
        }