public void BuildsFromList()
        {
            var root = new OpenApiPathItem {
                Summary = "Root"
            };
            var health = new OpenApiPathItem {
                Summary = "Health"
            };
            var usersA = new OpenApiPathItem {
                Summary = "Users A"
            };
            var usersB = new OpenApiPathItem {
                Summary = "Users B"
            };
            var paths = new OpenApiPaths
            {
                ["/"]        = root,
                ["/health"]  = health,
                ["/users/a"] = usersA,
                ["/users/b"] = usersB,
            };

            var tree = PathTree.From(paths);

            tree.Should().BeEquivalentTo(new PathTree
            {
                Item     = root,
                Children =
                {
                    ["health"] = new PathTree    {
                        Item = health
                    },
                    ["users"] = new PathTree
                                                 {
                                                 Children =
                                                 {
                                                 ["a"] = new PathTree {
                                                     Item = usersA
                                                 },
                                                 ["b"] = new PathTree {
                                                     Item = usersB
                                                 }
                                                 }
                                                 }
                }
            });
        }