public IReadOnlyList<Element> FindElements( 
   IEnumerable<string> elementNames
)

//Must be on QueuedTask
await QueuedTask.Run(() =>
{
  // Find specific elements by name
  var ge_rect = page.FindElement("Rectangle") as GraphicElement;
  var elements = new List<string>();
  elements.Add("Text");
  elements.Add("Polygon");
  var elems = page.FindElements(elements);

  //Get elements retaining hierarchy
  var top_level_elems = page.GetElements();

  //Flatten hierarchy
  var all_elems = page.GetFlattenedElements();

  //Use LINQ with any of the collections
  //Retrieve just those elements that are Visible
  var some_elems = all_elems.Where(ge => ge.IsVisible).ToList();
});

//Must be on QueuedTask
await QueuedTask.Run(() =>
{
  //Select/unselect some elements...
  var elems = activePage.GetFlattenedElements();
  //select any element not a group element
  activePage.SelectElements(elems.Where(e => !e.Name.StartsWith("Group")));
  activePage.UnSelectElements(elems.Where(e => !e.Name.StartsWith("Group")));

  //Select/unselect all visible, graphic elements
  var ge_elems = elems.Where(ge => ge.IsVisible).ToList();
  activePage.SelectElements(ge_elems);
  activePage.UnSelectElements(ge_elems);

  //Select/unselect a specific element
  var na = activePage.FindElement("My Text Element");
  activePage.SelectElement(na);
  activePage.UnSelectElement(na);

  //Select everything
  activePage.SelectElements(elems);

  //enumerate the selected elements
  foreach (var sel_elem in activePage.GetSelectedElements())
  {
    //TODO
  }
});