public Nullable<bool> IsVisible {get; set;}

//The catalog path of the feature layer to add to the map
var featureClassUriVisibility = new Uri(@"C:\Data\Admin\AdminData.gdb\USA\cities");
//Define the Feature Layer's parameters.
var layerParamsVisibility = new FeatureLayerCreationParams(featureClassUriVisibility)
{
  //Set visibility
  IsVisible = false,
};
//Create the layer with the feature layer parameters and add it to the active map
var createdFC = LayerFactory.Instance.CreateLayer<FeatureLayer>(layerParamsVisibility, MapView.Active.Map);

var url = @"https://geoeventsample1.esri.com:6443/arcgis/rest/services/AirportTraffics/StreamServer";
var uri = new Uri(url, UriKind.Absolute);
//Must be on QueuedTask!

var createParams = new FeatureLayerCreationParams(uri)
{
  IsVisible = false
};
var streamLayer = LayerFactory.Instance.CreateLayer<StreamLayer>(
                    createParams, map);
//Define the unique values by hand
var uvr = new CIMUniqueValueRenderer()
{
  Fields = new string[] { "ACTYPE" },
  UseDefaultSymbol = true,
  DefaultLabel = "Others",
  DefaultSymbol = SymbolFactory.Instance.ConstructPointSymbol(
              CIMColor.CreateRGBColor(185, 185, 185), 8, SimpleMarkerStyle.Hexagon).MakeSymbolReference()
};

var classes = new List<CIMUniqueValueClass>();
//add in classes - one for ACTYPE of 727, one for DC 9
classes.Add(
  new CIMUniqueValueClass() {
        Values = new CIMUniqueValue[] {
              new CIMUniqueValue() { FieldValues = new string[] { "B727" } } },
        Visible = true,
        Label = "Boeing 727",
        Symbol = SymbolFactory.Instance.ConstructPointSymbol(
              ColorFactory.Instance.RedRGB, 10, SimpleMarkerStyle.Hexagon).MakeSymbolReference()
});
classes.Add(
  new CIMUniqueValueClass()
  {
    Values = new CIMUniqueValue[] {
              new CIMUniqueValue() { FieldValues = new string[] { "DC9" } } },
    Visible = true,
    Label = "DC 9",
    Symbol = SymbolFactory.Instance.ConstructPointSymbol(
              ColorFactory.Instance.GreenRGB, 10, SimpleMarkerStyle.Hexagon).MakeSymbolReference()
  });
//add the classes to a group
var groups = new List<CIMUniqueValueGroup>()
{
  new CIMUniqueValueGroup() {
     Classes = classes.ToArray()
  }
};
//add the groups to the renderer
uvr.Groups = groups.ToArray();
//Apply the renderer (for current observations)
streamLayer.SetRenderer(uvr);
streamLayer.SetVisibility(true);//turn on the layer

//Must be on the QueuedTask.Run()

//Must be a .NetCDF file for voxels
var url = @"C:\MyData\AirQuality_Redlands.nc";
var cim_connection = new CIMVoxelDataConnection()
{
    URI = url
};
//Create a VoxelLayerCreationParams
var createParams = VoxelLayerCreationParams.Create(cim_connection);
createParams.IsVisible = true;

//Can also just use the path directly...
//var createParams = VoxelLayerCreationParams.Create(url);

//Use VoxelLayerCreationParams to enumerate the variables within
//the voxel
var variables = createParams.Variables;
foreach (var variable in variables)
{
    var line = $"{variable.Variable}: {variable.DataType}, " +
       $"{variable.Description}, {variable.IsDefault}, {variable.IsSelected}";
    System.Diagnostics.Debug.WriteLine(line);
}
//Optional: set the default variable
createParams.SetDefaultVariable(variables.Last());

//Create the layer - map must be a local scene
VoxelLayer voxelLayer = LayerFactory.Instance.CreateLayer<VoxelLayer>(createParams, map);

var sceneLayerUrl = @"https://myportal.com/server/rest/services/Hosted/SceneLayerServiceName/SceneServer";
//portal items also ok as long as the portal is the current active portal...
//var sceneLayerUrl = @"https://myportal.com/home/item.html?id=123456789abcdef1234567890abcdef0";

await QueuedTask.Run(() =>
{
  //Create with initial visibility set to false. Add to current scene
  var createparams = new LayerCreationParams(new Uri(sceneLayerUrl, UriKind.Absolute))
  {
    IsVisible = false
  };

  //cast to specific type of scene layer being created - in this case FeatureSceneLayer
  var sceneLayer = LayerFactory.Instance.CreateLayer<Layer>(
           createparams, MapView.Active.Map) as FeatureSceneLayer;
  //or...specify the cast directly
  var sceneLayer2 = LayerFactory.Instance.CreateLayer<FeatureSceneLayer>(
           createparams, MapView.Active.Map);
  //ditto for BuildingSceneLayer, PointCloudSceneLayer, IntegratedMeshSceneLayer
  //...
});