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

//Create a group using a list of element names at the root level of the contents pane.

//Build list of element names
var elmNameList = new[] { "Table Frame", "Chart Frame" };

//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //GroupElement groupWithListOfElementNamesAtRoot = LayoutElementFactory.Instance.CreateGroupElement(layout, elmNameList);
  //groupWithListOfElementNamesAtRoot.SetName("Group with list of element names at root");

  //At 3.x use FindElements to retrieve the respective elements first
  var elems = layout.FindElements(elmNameList);
  GroupElement groupWithListOfElementNamesAtRoot =
    ElementFactory.Instance.CreateGroupElement(layout, elems, "Group with list of element names at root");
});

//Create a group with a list of elements at the root level of the contents pane.

//Find an existing elements
//container is IElementContainer - GroupLayer or Layout
var elem1 = container.FindElement("Polygon 1");
var elem2 = container.FindElement("Bezier Text");
var elem3 = container.FindElement("Cloud Shape 2");

//Construct a list and add the elements
var elmList = new List<Element>
{
  elem1,
  elem2,
  elem3
};

//Perform on the worker thread
await QueuedTask.Run(() =>
{
  //At 2.x - GroupElement groupWithListOfElementsAtRoot =
  //             LayoutElementFactory.Instance.CreateGroupElement(layout, elmList);
  //groupWithListOfElementsAtRoot.SetName("Group with list of elements at root");
  //
  GroupElement groupWithListOfElementsAtRoot =
          ElementFactory.Instance.CreateGroupElement(
                   container, elmList, "Group with list of elements at root");
});

// *** or ***

//Create a group using a list of element names at the root level of the contents pane.

//List of element names
var elmNameList = new[] { "Para Text1", "Line 3" };

//Perform on the worker thread
await QueuedTask.Run(() =>
{
  //At 2.x - GroupElement groupWithListOfElementNamesAtRoot =
  //   LayoutElementFactory.Instance.CreateGroupElement(layout, elmNameList);
  //         groupWithListOfElementNamesAtRoot.SetName(
  //                  "Group with list of element names at root");

  //At 3.x, use the names to find the relevant elements first
  //container is IElementContainer - GroupLayer or Layout
  var elems = container.FindElements(elmNameList);
  GroupElement groupWithListOfElementNamesAtRoot =
      ElementFactory.Instance.CreateGroupElement(
           container, elems, "Group with list of element names at root");
});

//Create a group with a list of elements at the root level of the contents pane.

//Find an existing elements
//container is IElementContainer - GroupLayer or Layout
var elem1 = container.FindElement("Polygon 1");
var elem2 = container.FindElement("Bezier Text");
var elem3 = container.FindElement("Cloud Shape 2");

//Construct a list and add the elements
var elmList = new List<Element>
{
  elem1,
  elem2,
  elem3
};

//Perform on the worker thread
await QueuedTask.Run(() =>
{
  //At 2.x - GroupElement groupWithListOfElementsAtRoot =
  //             LayoutElementFactory.Instance.CreateGroupElement(layout, elmList);
  //groupWithListOfElementsAtRoot.SetName("Group with list of elements at root");
  //
  GroupElement groupWithListOfElementsAtRoot =
          ElementFactory.Instance.CreateGroupElement(
                   container, elmList, "Group with list of elements at root");
});

// *** or ***

//Create a group using a list of element names at the root level of the contents pane.

//List of element names
var elmNameList = new[] { "Para Text1", "Line 3" };

//Perform on the worker thread
await QueuedTask.Run(() =>
{
  //At 2.x - GroupElement groupWithListOfElementNamesAtRoot =
  //   LayoutElementFactory.Instance.CreateGroupElement(layout, elmNameList);
  //         groupWithListOfElementNamesAtRoot.SetName(
  //                  "Group with list of element names at root");

  //At 3.x, use the names to find the relevant elements first
  //container is IElementContainer - GroupLayer or Layout
  var elems = container.FindElements(elmNameList);
  GroupElement groupWithListOfElementNamesAtRoot =
      ElementFactory.Instance.CreateGroupElement(
           container, elems, "Group with list of element names at root");
});

//on the QueuedTask
//Find elements by name
var layoutElementsToFind = layout.FindElements(new List<string>() { "Point 1", "Line 3", "Text 1" });
//Get the collection of elements from the page layout. Nesting within GroupElement is preserved.
var elementCollection = layout.GetElements();
//Get the collection of Element from the page layout as a flattened list. Nested groups within GroupElement are not preserved.
var elements = layout.GetElementsAsFlattenedList();
//Convert collection of the elements to a collection of GraphicElements.
var graphicElements = elements.ToList().ConvertAll(x => (GraphicElement)x);
//Find elements by type
//Find all point graphics in the Layout
var pointGraphics = graphicElements.Where(elem => elem.GetGraphic() is CIMPointGraphic);
//Find all line graphics in the Graphics Layer
var lineGraphics = graphicElements.Where(elem => elem.GetGraphic() is CIMLineGraphic);
////Find all polygon graphics in the Graphics Layer
var polyGraphics = graphicElements.Where(elem => elem.GetGraphic() is CIMPolygonGraphic);
////Find all text graphics in the Graphics Layer
var textGraphics = graphicElements.Where(elem => elem.GetGraphic() is CIMTextGraphic);
////Find all picture graphics in the Graphics Layer
var pictureGraphic = graphicElements.Where(elem => elem.GetGraphic() is CIMPictureGraphic);

//Unselect one element.
var elementToUnSelect = layout.FindElements(new List<string>() { "MyPoint" }).FirstOrDefault();
layout.UnSelectElement(elementToUnSelect);
//Unselect multiple elements.
var elementsToUnSelect = layout.FindElements(new List<string>() { "Point 1", "Line 3", "Text 1" });
layout.UnSelectElements(elementsToUnSelect);

LayoutView layoutView = LayoutView.Active;
//Unselect one element.
var elementToUnSelectInView = layout.FindElements(new List<string>() { "MyPoint" }).FirstOrDefault();
layoutView.UnSelectElement(elementToUnSelect);
//Unselect multiple elements.
var elementsToUnSelectInView = layout.FindElements(new List<string>() { "Point 1", "Line 3", "Text 1" });
layoutView.UnSelectElements(elementsToUnSelect);

LayoutView lytView = LayoutView.Active;
//Zoom to an element
var elementToZoomTo = layout.FindElements(new List<string>() { "MyPoint" }).FirstOrDefault();
lytView.ZoomToElement(elementToZoomTo);
//Zoom to  multiple elements.
var elementsToZoomTo = layout.FindElements(new List<string>() { "Point 1", "Line 3", "Text 1" });
lytView.ZoomToElements(elementsToZoomTo);