public IReadOnlyList<TopologyNode> GetNodes()

private async Task BuildGraphWithActiveView()
{
  await QueuedTask.Run(() =>
  {
    //Build the map topology graph
    MapView.Active.BuildMapTopologyGraph<TopologyDefinition>(async topologyGraph =>
    {
      //Getting the nodes and edges present in the graph
      var topologyGraphNodes = topologyGraph.GetNodes();
      var topologyGraphEdges = topologyGraph.GetEdges();

      foreach (var node in topologyGraphNodes)
      {
        // do something with the node
      }
      foreach (var edge in topologyGraphEdges)
      {
        // do something with the edge
      }

      MessageBox.Show($"Number of topo graph nodes are:  {topologyGraphNodes.Count}.\n Number of topo graph edges are {topologyGraphEdges.Count}.", "Map Topology Info");
    });
  });
}