public CIMGraphic GetGraphic()

//within a queued Task
//get the first line element in the layer
var ge = graphicsLayer.FindElement("Line 10") as GraphicElement;
var graphic = ge.GetGraphic();
if (graphic is CIMLineGraphic lineGraphic)
{
  //change its symbol
  lineGraphic.Symbol =
   SymbolFactory.Instance.ConstructLineSymbol(
     SymbolFactory.Instance.ConstructStroke(
 ColorFactory.Instance.BlueRGB, 2, SimpleLineStyle.DashDot)).MakeSymbolReference();
  //apply the change
  ge.SetGraphic(lineGraphic);
}

//Create polygon paragraph text with basic text properties.

//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //Build geometry
  List<Coordinate2D> plyCoords = new List<Coordinate2D>();
  plyCoords.Add(new Coordinate2D(3.5, 7));
  plyCoords.Add(new Coordinate2D(4.5, 7));
  plyCoords.Add(new Coordinate2D(4.5, 6.7));
  plyCoords.Add(new Coordinate2D(5.5, 6.7));
  plyCoords.Add(new Coordinate2D(5.5, 6.1));
  plyCoords.Add(new Coordinate2D(3.5, 6.1));
  //At 2.x - Polygon poly = PolygonBuilder.CreatePolygon(plyCoords);
  Polygon poly = PolygonBuilderEx.CreatePolygon(plyCoords);

  //Set symbolology, create and add element to layout
  CIMTextSymbol sym = SymbolFactory.Instance.ConstructTextSymbol(ColorFactory.Instance.GreyRGB, 10, "Arial", "Regular");
  string text = "Some Text String that is really long and is <BOL>forced to wrap to other lines</BOL> so that we can see the effects." as String;
  //At 2.x - GraphicElement polyTxtElm = LayoutElementFactory.Instance.CreatePolygonParagraphGraphicElement(layout, poly, text, sym);
  //         polyTxtElm.SetName("New Polygon Text"); 
  GraphicElement polyTxtElm = ElementFactory.Instance.CreateTextGraphicElement(
                                layout, TextType.RectangleParagraph, poly, sym, text, "New Polygon Text");

  //(Optionally) Modify paragraph border 
  CIMGraphic polyTxtGra = polyTxtElm.GetGraphic();
  CIMParagraphTextGraphic cimPolyTxtGra = polyTxtGra as CIMParagraphTextGraphic;
  cimPolyTxtGra.Frame.BorderSymbol = new CIMSymbolReference();
  cimPolyTxtGra.Frame.BorderSymbol.Symbol = SymbolFactory.Instance.ConstructLineSymbol(ColorFactory.Instance.GreyRGB, 1.0, SimpleLineStyle.Solid);
  polyTxtElm.SetGraphic(polyTxtGra);
});

//Create circle paragraph text with basic text settings and optionally a modified border.

//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //Build geometry
  Coordinate2D center = new Coordinate2D(4.5, 4);
  //At 2.x - EllipticArcBuilder eabCir = new EllipticArcBuilder(center, 0.5, esriArcOrientation.esriArcClockwise);
  var eabCir = new EllipticArcBuilderEx(center, 0.5, ArcOrientation.ArcClockwise);
  EllipticArcSegment cir = eabCir.ToSegment();
  var polyCir = PolygonBuilderEx.CreatePolygon(
                  PolylineBuilderEx.CreatePolyline(cir));

  //Set symbolology, create and add element to layout
  CIMTextSymbol sym = SymbolFactory.Instance.ConstructTextSymbol(ColorFactory.Instance.GreenRGB, 10, "Arial", "Regular");
  string text = "Circle, circle, circle, circle, circle, circle, circle, circle, circle, circle, circle";
  //At 2.x - GraphicElement cirTxtElm = LayoutElementFactory.Instance.CreateCircleParagraphGraphicElement(layout, cir, text, sym);
  //         cirTxtElm.SetName("New Circle Text");
  GraphicElement cirTxtElm = ElementFactory.Instance.CreateTextGraphicElement(
                                layout, TextType.CircleParagraph, polyCir, sym, text, "New Circle Text");

  //(Optionally) Modify paragraph border 
  CIMGraphic cirTxtGra = cirTxtElm.GetGraphic();
  CIMParagraphTextGraphic cimCirTxtGra = cirTxtGra as CIMParagraphTextGraphic;
  cimCirTxtGra.Frame.BorderSymbol = new CIMSymbolReference();
  cimCirTxtGra.Frame.BorderSymbol.Symbol = SymbolFactory.Instance.ConstructLineSymbol(ColorFactory.Instance.GreyRGB, 1.0, SimpleLineStyle.Solid);
  cirTxtElm.SetGraphic(cirTxtGra);
});

//Create ellipse paragraph text with basic text settings and optionally a modified border.

//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //Build geometry
  Coordinate2D center = new Coordinate2D(4.5, 2.75);
  //At 2.x - EllipticArcBuilder eabElp = new EllipticArcBuilder(center, 0, 1, 0.45, esriArcOrientation.esriArcClockwise);
  var eabElp = new EllipticArcBuilderEx(center, 0, 1, 0.45, ArcOrientation.ArcClockwise);
  EllipticArcSegment ellipse = eabElp.ToSegment();
  var polyElp = PolygonBuilderEx.CreatePolygon(
                  PolylineBuilderEx.CreatePolyline(ellipse));

  //Set symbolology, create and add element to layout
  CIMTextSymbol sym = SymbolFactory.Instance.ConstructTextSymbol(ColorFactory.Instance.BlueRGB, 10, "Arial", "Regular");
  string text = "Ellipse, ellipse, ellipse, ellipse, ellipse, ellipse, ellipse, ellipse, ellipse, ellipse, ellipse, ellipse";
  //At 2.x - GraphicElement elpTxtElm = LayoutElementFactory.Instance.CreateEllipseParagraphGraphicElement(layout, ellipse, text, sym);
  //         elpTxtElm.SetName("New Ellipse Text");
  GraphicElement elpTxtElm = ElementFactory.Instance.CreateTextGraphicElement(
                                layout, TextType.EllipseParagraph, polyElp, sym, text, "New Ellipse Text");

  //(Optionally) Modify paragraph border 
  CIMGraphic elpTxtGra = elpTxtElm.GetGraphic();
  CIMParagraphTextGraphic cimElpTxtGra = elpTxtGra as CIMParagraphTextGraphic;
  cimElpTxtGra.Frame.BorderSymbol = new CIMSymbolReference();
  cimElpTxtGra.Frame.BorderSymbol.Symbol = SymbolFactory.Instance.ConstructLineSymbol(ColorFactory.Instance.GreyRGB, 1.0, SimpleLineStyle.Solid);
  elpTxtElm.SetGraphic(elpTxtGra);
});

//This example references a graphic element on a layout and sets its Transparency property (which is not available in the managed API)
//by accessing the element's CIMGraphic.

//Added references
using ArcGIS.Core.CIM;                             //CIM
using ArcGIS.Desktop.Core;                         //Project
using ArcGIS.Desktop.Layouts;                      //Layout class
using ArcGIS.Desktop.Framework.Threading.Tasks;    //QueuedTask

public class GraphicElementExample1
{
  public static Task<bool> UpdateElementTransparencyAsync(string LayoutName, string ElementName, int TransValue)
  {
    //Reference a layoutitem in a project by name
    LayoutProjectItem layoutItem = Project.Current.GetItems<LayoutProjectItem>().FirstOrDefault(item => item.Name.Equals(LayoutName));
    if (layoutItem == null)
      return Task.FromResult(false);

    return QueuedTask.Run<bool>(() =>
    {
      //Reference and load the layout associated with the layout item
      Layout lyt = layoutItem.GetLayout();

      //Reference a element by name
      GraphicElement graElm = lyt.FindElement(ElementName) as GraphicElement;
      if (graElm == null)
        return false;

      //Modify the Transparency property that exists only in the CIMGraphic class.
      CIMGraphic CIMGra = graElm.GetGraphic() as CIMGraphic;
      CIMGra.Transparency = TransValue;             //e.g., TransValue = 50
      graElm.SetGraphic(CIMGra);

      return true;
    });
  }
}

//Note: must call within QueuedTask.Run() 
var CIMGra = graElm.GetGraphic() as CIMGraphic;
//TODO - make changes to CIMGraphic
//...
graElm.SetGraphic(CIMGra);

//Create rectangle text with background and border symbology.  

//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //Build 2D polygon geometry
  List<Coordinate2D> plyCoords = new List<Coordinate2D>();
  plyCoords.Add(new Coordinate2D(3.5, 7));
  plyCoords.Add(new Coordinate2D(4.5, 7));
  plyCoords.Add(new Coordinate2D(4.5, 6.7));
  plyCoords.Add(new Coordinate2D(5.5, 6.7));
  plyCoords.Add(new Coordinate2D(5.5, 6.1));
  plyCoords.Add(new Coordinate2D(3.5, 6.1));
  //At 2.x - Polygon poly = PolygonBuilder.CreatePolygon(plyCoords);
  Polygon poly = PolygonBuilderEx.CreatePolygon(plyCoords);

  //Set symbology, create and add element to layout
  //Also notice how formatting tags are using within the text string.
  CIMTextSymbol sym = SymbolFactory.Instance.ConstructTextSymbol(
                    ColorFactory.Instance.GreyRGB, 10, "Arial", "Regular");
  string text = "Some Text String that is really long and is " +
                "<BOL>forced to wrap to other lines</BOL> so that " +
                "we can see the effects." as String;
  //At 2.x - GraphicElement polyTxtElm =
  //           LayoutElementFactory.Instance.CreatePolygonParagraphGraphicElement(
  //                                      layout, poly, text, sym);
  //         polyTxtElm.SetName("New Polygon Text");

  GraphicElement polyTxtElm = ElementFactory.Instance.CreateTextGraphicElement(
    container, TextType.RectangleParagraph, poly, sym, text, "Polygon Paragraph");

  //(Optionally) Modify paragraph border 
  CIMGraphic polyTxtGra = polyTxtElm.GetGraphic();
  CIMParagraphTextGraphic cimPolyTxtGra = polyTxtGra as CIMParagraphTextGraphic;
  cimPolyTxtGra.Frame.BorderSymbol = new CIMSymbolReference();
  cimPolyTxtGra.Frame.BorderSymbol.Symbol =
               SymbolFactory.Instance.ConstructLineSymbol(
                          ColorFactory.Instance.GreyRGB, 1.0, SimpleLineStyle.Solid);
  polyTxtElm.SetGraphic(polyTxtGra);
});

//Create a picture element and also set background and border symbology.

//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //Build 2D envelope geometry
  Coordinate2D pic_ll = new Coordinate2D(6, 1);
  Coordinate2D pic_ur = new Coordinate2D(8, 2);
  //At 2.x - Envelope env = EnvelopeBuilder.CreateEnvelope(pic_ll, pic_ur);
  Envelope env = EnvelopeBuilderEx.CreateEnvelope(pic_ll, pic_ur);

  //Create and add element to layout
  string picPath = @"C:\Temp\WhitePass.jpg";
  //At 2.x - GraphicElement picElm =
  //    LayoutElementFactory.Instance.CreatePictureGraphicElement(
  //                                             layout, env, picPath);
  //         picElm.SetName("New Picture");
  //
  GraphicElement picElm = ElementFactory.Instance.CreatePictureGraphicElement(
                                       layout, env, picPath, "New Picture");

  //(Optionally) Modify the border and shadow 
  CIMGraphic picGra = picElm.GetGraphic();
  CIMPictureGraphic cimPicGra = picGra as CIMPictureGraphic;
  cimPicGra.Frame.BorderSymbol = new CIMSymbolReference();
  cimPicGra.Frame.BorderSymbol.Symbol =
        SymbolFactory.Instance.ConstructLineSymbol(
               ColorFactory.Instance.BlueRGB, 2.0, SimpleLineStyle.Solid);

  cimPicGra.Frame.ShadowSymbol = new CIMSymbolReference();
  cimPicGra.Frame.ShadowSymbol.Symbol =
              SymbolFactory.Instance.ConstructPolygonSymbol(
                    ColorFactory.Instance.BlackRGB, SimpleFillStyle.Solid);

  //Update the element
  picElm.SetGraphic(picGra);
});

//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);

//Update an element's transparency using the CIM.

//Perform on the worker thread
QueuedTask.Run(() =>
{
  // Reference and load the layout associated with the layout item
  Layout layout = layoutItem.GetLayout();
  if (layout != null)
  {
    // Reference a element by name
    GraphicElement graphicElement = layout.FindElement("MyElement") as GraphicElement;
    if (graphicElement != null)
    {
      // Modify the Transparency property that exists only in the CIMGraphic class.
      CIMGraphic CIMGraphic = graphicElement.GetGraphic() as CIMGraphic;
      CIMGraphic.Transparency = 50; // mark it 50% transparent
      graphicElement.SetGraphic(CIMGraphic);
    }
  }
});

//This is the gap between two fields
double fieldIncrement = 0.9388875113593206276389;
//On the QueuedTask
//New field to add.
var newReportField = new CIMReportField
{
  Name = "POP1990",
  FieldOrder = 2,
};
//Get the "ReportSection element"                
var mainReportSection = report.Elements.OfType<ReportSection>().FirstOrDefault();
if (mainReportSection == null) return;

//Get the "ReportDetails" within the ReportSectionElement. ReportDetails is where "fields" are.
var reportDetailsSection = mainReportSection?.Elements.OfType<ReportDetails>().FirstOrDefault();
if (reportDetailsSection == null) return;

//Within ReportDetails find the envelope that encloses a field.
//We get the first CIMParagraphTextGraphic in the collection so that we can add the new field next to it.                    
var lastFieldGraphic = reportDetailsSection.Elements.FirstOrDefault((r) =>
{
  var gr = r as GraphicElement;
  if (gr == null) return false;
  return (gr.GetGraphic() is CIMParagraphTextGraphic ? true : false);
});
//Get the Envelope of the last field
var graphicBounds = lastFieldGraphic.GetBounds();

//Min and Max values of the envelope
var xMinOfFieldEnvelope = graphicBounds.XMin;
var yMinOfFieldEnvelope = graphicBounds.YMin;

var xMaxOfFieldEnvelope = graphicBounds.XMax;
var YMaxOfFieldEnvelope = graphicBounds.YMax;
//create the new Envelope to be offset from the existing field
//At 2.x
//MapPoint newMinPoint = MapPointBuilder.CreateMapPoint(xMinOfFieldEnvelope + fieldIncrement, yMinOfFieldEnvelope);
//MapPoint newMaxPoint = MapPointBuilder.CreateMapPoint(xMaxOfFieldEnvelope + fieldIncrement, YMaxOfFieldEnvelope);
//Envelope newFieldEnvelope = EnvelopeBuilder.CreateEnvelope(newMinPoint, newMaxPoint);

MapPoint newMinPoint = MapPointBuilderEx.CreateMapPoint(xMinOfFieldEnvelope + fieldIncrement, yMinOfFieldEnvelope);
MapPoint newMaxPoint = MapPointBuilderEx.CreateMapPoint(xMaxOfFieldEnvelope + fieldIncrement, YMaxOfFieldEnvelope);
Envelope newFieldEnvelope = EnvelopeBuilderEx.CreateEnvelope(newMinPoint, newMaxPoint);

//Create field
GraphicElement fieldGraphic = ReportElementFactory.Instance.CreateFieldValueTextElement(reportDetailsSection, newFieldEnvelope, newReportField);