public void SetDefaultVariable( 
   VoxelVariableCreationParams variable
)

{
  // Note: call within 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 = LayerFactory.Instance.CreateLayer<VoxelLayer>(createParams, map);
  }
}