public ParallelOffset.Builder()

// Creates parallel offset features from the selected features.
await QueuedTask.Run(static () =>
  {
    //Create parallel features from the selected features

    //find the roads layer
    var roadsLayer = MapView.Active.Map.FindLayers("Roads")?[0];

    //instantiate parallelOffset builder and set parameters
    var parOffsetBuilder = new ParallelOffset.Builder()
    {
      Selection = MapView.Active.Map.GetSelection(),
      Template = roadsLayer.GetTemplate("Freeway"),
      Distance = 200,
      Side = ParallelOffset.SideType.Both,
      Corner = ParallelOffset.CornerType.Mitered,
      Iterations = 1,
      AlignConnected = false,
      CopyToSeparateFeatures = false,
      RemoveSelfIntersectingLoops = true
    };

    //create EditOperation and execute
    var parallelOp = new EditOperation();
    parallelOp.Create(parOffsetBuilder);
    if (!parallelOp.IsEmpty)
    {
      var result = parallelOp.Execute(); //Execute and ExecuteAsync will return true if the operation was successful and false if not
    }
  });