public class ClassFlag 

{
  // Note: call within QueuedTask.Run()
  {
    var filters = pointCloudSceneLayer.GetFilters();
    PointCloudFilterDefinition fdef = null;
    if (filters.Count() == 0)
    {
      fdef = new PointCloudFilterDefinition()
      {
        //7 is "edge of flight line" - exclude
        ClassFlags = new List<ClassFlag> {
         new ClassFlag(7, ClassFlagOption.Exclude) }
      };
    }
    else
    {
      fdef = PointCloudFilterDefinition.FromCIM(filters);
      //keep any include or ignore class flags
      var keep = fdef.ClassFlags.Where(
             cf => cf.ClassFlagOption != ClassFlagOption.Exclude).ToList();
      //7 is "edge of flight line" - exclude
      keep.Add(new ClassFlag(7, ClassFlagOption.Exclude));
      fdef.ClassFlags = keep;
    }
    //apply
    pointCloudSceneLayer.SetFilters(fdef.ToCIM());
  }
}