public void WhenAddLeafCommandAndRepoDoesNotContainSpecifiedTree_ExpectException()
        {
            var value          = 321;
            var treeController = new TreeController(_treeRepo.Object, _treeFactory.Object);

            treeController.AddLeaf(new AddLeafCommand()
            {
                Value = value, TreeId = It.IsAny <Guid>()
            });
        }
        public void WhenAddLeafCommand_ExpectAddLeafCalledOnTree()
        {
            var value = 321;
            var tree  = new Mock <ITree>();

            _treeRepo.Setup(x => x.GetById(It.IsAny <Guid>())).Returns(tree.Object);
            var treeController = new TreeController(_treeRepo.Object, _treeFactory.Object);

            treeController.AddLeaf(new AddLeafCommand()
            {
                Value = value, TreeId = It.IsAny <Guid>()
            });
            tree.Verify(x => x.AddLeaf(value));
        }