public ObservableCollection<Node> FillProjects()
        {
            var comm = new Command(DatabaseManager.Instance.Connection);
            var nodes = new ObservableCollection<Node>();

            var Freelancers = DatabaseLoader.ComputeFreelansers(comm).ToList();
            //var Costumers = DatabaseLoader.ComputeCostumers(comm).ToList();
            var Tasks = DatabaseLoader.ComputeTasks(comm).ToList();
            var Projects = DatabaseLoader.ComputeProjects(comm).ToList();

            foreach(var project in Projects)
            {
                Node nodeProject = project;
                Node nodeLead = Freelancers.Where(p => p.PersonId == project.TeamLeadId).First();
                foreach (var task in Tasks)
                {
                    if (task.ProjectId == project.Idproject)
                    {
                        Node node = task;
                        foreach (var freelancer in Freelancers)
                        {
                            if (freelancer.PersonId == task.ExecutorId)
                            {

                                node.Children.Add(freelancer);
                            }

                        }
                        nodeProject.Children.Add(node);
                    }
                }

                nodes.Add(nodeProject);
                if (nodeLead!=null)
                    nodeProject.Children.Add(nodeLead);

            }

            Node temp = new HeaderNode();
            temp.Text = "Projects";
            temp.IsExpanded = true;
            foreach (var node in nodes)
                temp.Children.Add(node);

            var tempList = new ObservableCollection<MVVM.Node>();
            tempList.Add(temp);
            return tempList;
        }
        public ObservableCollection<Node> FillFreelancer()
        {
            var comm = new Command(DatabaseManager.Instance.Connection);
            var nodes = new ObservableCollection<Node>();

            var Freelancers = DatabaseLoader.ComputeFreelansers(comm).ToList();
            //var Costumers = DatabaseLoader.ComputeCostumers(comm).ToList();
            var Tasks = DatabaseLoader.ComputeTasks(comm).ToList();
            //var Projects = DatabaseLoader.ComputeProjects(comm).ToList();

            foreach (var freelancer in Freelancers)
            {
                Node parentNode = freelancer;

                foreach (var task in Tasks)
                {
                    if (task.Id == freelancer.PersonId)
                    {
                        Node childNode = task;
                        parentNode.Children.Add(task);
                    }
                }
                nodes.Add(parentNode);

            }

            Node temp = new MVVM.HeaderNode();
            temp.Text = "Freelancers";
            temp.IsExpanded = true;
            foreach (var node in nodes)
                temp.Children.Add(node);

            var tempList = new ObservableCollection<MVVM.Node>();
            tempList.Add(temp);
            return tempList;
        }