static async void Composite(string path)
        {
            WebCrawler crawler = WebCrawler.GetInstance();

            HtmlStoreProxy proxy = new HtmlStoreProxy();

            MyHtmlModel model = await proxy.GetMyHtmlModel(path);

            HtmlDocument htmlDoc = new HtmlDocument();

            htmlDoc.LoadHtml(model.HTML);


            HtmlNode html = crawler.GetFirstNode("html", htmlDoc);

            var bodyNode = html.SelectSingleNode("//body");

            var navigationNode = crawler.GetNode
                                 (
                "class",
                "navbar navbar-expand-lg navbar-light fixed-top",
                htmlDoc
                                 );
            var headerNode = crawler.GetNode
                             (
                "class",
                "masthead",
                htmlDoc
                             );
            var aboutSectionNode = crawler.GetNode
                                   (
                "id",
                "about",
                htmlDoc
                                   );
            var signupSection = crawler.GetNode
                                (
                "id",
                "signup",
                htmlDoc
                                );

            var contentOfsignupSection = crawler.GetFirstNode("body/section[3]/div[1]", htmlDoc);

            signupSection.RemoveAllChildren();


            html.RemoveChild(bodyNode);//html tag is without body tag

            Console.WriteLine(html.OuterHtml);

            ////////////////Composite realization

            Composite.Component htmlComposite = new CompositeComponent
                                                (
                new MyHtmlModel()
            {
                HTML = html.OuterHtml, Name = "WithoutBody"
            }
                                                );
            htmlComposite.Node = html;


            bodyNode.RemoveAllChildren();//body tag is empty

            //composite components
            Composite.Component EmptyBody = new CompositeComponent
                                            (
                new MyHtmlModel()
            {
                HTML = bodyNode.OuterHtml, Name = "EmptyBody"
            }
                                            );
            EmptyBody.Node = bodyNode;

            //leaf
            HtmlElem navigation = new HtmlElem(new MyHtmlModel()
            {
                HTML = navigationNode.OuterHtml,
                Name = "NavBar"
            });

            navigation.Node = navigationNode;

            //leaf
            HtmlElem header = new HtmlElem(new MyHtmlModel()
            {
                HTML = headerNode.OuterHtml,
                Name = "Header"
            });

            header.Node = headerNode;

            //leaf
            HtmlElem AboutSection = new HtmlElem(new MyHtmlModel()
            {
                HTML = aboutSectionNode.OuterHtml,
                Name = "NavBar"
            });

            AboutSection.Node = aboutSectionNode;

            //append children to body
            EmptyBody.Add(navigation);
            EmptyBody.Node.AppendChild(navigation.Node);

            EmptyBody.Add(header);
            EmptyBody.Node.AppendChild(header.Node);

            EmptyBody.Add(AboutSection);
            EmptyBody.Node.AppendChild(AboutSection.Node);

            htmlComposite.Add(EmptyBody);
            htmlComposite.Node.AppendChild(EmptyBody.Node);

            htmlComposite.Display();//displaying tree

            Console.WriteLine("--------------------htmlComposite html----------------");

            Console.WriteLine(htmlComposite.Node.OuterHtml); //displaying node html

            EmptyBody.Remove(AboutSection);                  //remove child
            EmptyBody.Node.RemoveChild(AboutSection.Node);   //remove node

            Console.WriteLine("--------------------htmlComposite html after remove----------------");

            Console.WriteLine(htmlComposite.Node.OuterHtml);//displaying body without child

            EmptyBody.Add(AboutSection);
            EmptyBody.Node.AppendChild(AboutSection.Node);

            //add one more composite element
            Composite.Component signUpSectionComposite = new CompositeComponent
                                                             (new MyHtmlModel()
            {
                HTML = signupSection.OuterHtml,
                Name = "EmptySignUpSection"
            });
            signUpSectionComposite.Node = signupSection;

            //leaf
            HtmlElem signUpSectionContainer = new HtmlElem
                                              (
                new MyHtmlModel()
            {
                HTML = contentOfsignupSection.OuterHtml,
                Name = "SignUpSectionContainer"
            }
                                              );

            signUpSectionContainer.Node = contentOfsignupSection;

            signUpSectionComposite.Add(signUpSectionContainer);
            signUpSectionComposite.Node.AppendChild(signUpSectionContainer.Node);

            EmptyBody.Add(signUpSectionComposite);
            EmptyBody.Node.AppendChild(signUpSectionComposite.Node);

            htmlComposite.Display();

            Console.WriteLine("--------------------htmlComposite html----------------");

            Console.WriteLine(htmlComposite.Node.OuterHtml);

            //htmlComposite.MyHtmlmodel.HTML=htmlComposite.Node.OuterHtml;//saving all html

            MyHtmlModel final = new MyHtmlModel()
            {
                HTML = htmlComposite.MyHtmlmodel.HTML,
                Name = "ResultOfComposition"
            };

            try
            {
                GenericSerializer serializer = new GenericSerializer("res", @"E:\studying\education\6сем\трпз\lab5\Saves\");
                serializer.BinarySerializing(FileMode.Create, final);
                serializer.DataContractSerialization(FileMode.Create, typeof(MyHtmlModel), final);
            }
            catch (Exception e)
            {
            }
            EmptyBody.Remove(header);                //remove child
            EmptyBody.Node.RemoveChild(header.Node); //remove node
            htmlComposite.Display();
        }