/// <summary>
        /// Load graph from the file
        /// </summary>
        /// <param name="graphLayout"></param>
        public void LoadGraphFromFile(ref GraphLayoutCity graphLayout)
        {
            var openGraphWindow = new OpenGraphWindow();

            openGraphWindow.ShowDialog();

            if (openGraphWindow.getResult())
            {
                citiesLocations   = openGraphWindow.getLocations();
                citiesConnections = openGraphWindow.getConnections();

                defaultCitiesLocations.Copy(citiesLocations);
                defaultCitiesConnections.Copy(citiesConnections);

                CreateGraph();
                RefreshGraph(ref graphLayout);
                EstablishGraphCoordinates(ref graphLayout);
            }
        }
 /// <summary>
 /// Recover the default graph data, which was downloaded from the initial
 /// file.
 /// </summary>
 private void RecoverGraphData()
 {
     citiesLocations.Copy(defaultCitiesLocations);
     citiesConnections.Copy(defaultCitiesConnections);
 }