public static Polyline CreatePolyline( 
   IEnumerable<Segment> segments,
   SpatialReference spatialReference
)

ICollection<Segment> collection = new List<Segment>();
polyline.GetAllSegments(ref collection);
int numSegments = collection.Count;    // = 10

IList<Segment> iList = collection as IList<Segment>;
for (int i = 0; i < numSegments; i++)
{
  // do something with iList[i]
}

// use the segments to build another polyline
Polyline polylineFromSegments = PolylineBuilderEx.CreatePolyline(collection);

//Create a graphic freehand element with a simple line style.

//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //Build geometry
  List<Coordinate2D> plCoords = new List<Coordinate2D>();
  plCoords.Add(new Coordinate2D(1.5, 10.5));
  plCoords.Add(new Coordinate2D(1.25, 9.5));
  plCoords.Add(new Coordinate2D(1, 10.5));
  plCoords.Add(new Coordinate2D(0.75, 9.5));
  plCoords.Add(new Coordinate2D(0.5, 10.5));
  plCoords.Add(new Coordinate2D(0.5, 1));
  plCoords.Add(new Coordinate2D(0.75, 2));
  plCoords.Add(new Coordinate2D(1, 1));
  //At 2.x - Polyline linePl = PolylineBuilder.CreatePolyline(plCoords);
  Polyline linePl = PolylineBuilderEx.CreatePolyline(plCoords);

  //Set symbolology, create and add element to layout
  CIMLineSymbol lineSym = SymbolFactory.Instance.ConstructLineSymbol(ColorFactory.Instance.BlackRGB, 2.0, SimpleLineStyle.Solid);
  //At 2.x - GraphicElement lineElm = LayoutElementFactory.Instance.CreateLineGraphicElement(layout, linePl, lineSym);
  //         lineElm.SetName("New Freehand"); 
  GraphicElement lineElm = ElementFactory.Instance.CreateGraphicElement(layout, linePl, lineSym, "New Freehand");
});

//Create an ellipse graphic with simple line and fill styles.

//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //Build geometry
  Coordinate2D center = new Coordinate2D(2, 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();

  //Set symbolology, create and add element to layout
  CIMStroke outline = SymbolFactory.Instance.ConstructStroke(ColorFactory.Instance.GreenRGB, 2.0, SimpleLineStyle.Dot);
  CIMPolygonSymbol ellipseSym = SymbolFactory.Instance.ConstructPolygonSymbol(ColorFactory.Instance.GreyRGB, SimpleFillStyle.Vertical, outline);
  //At 2.x - GraphicElement elpElm = LayoutElementFactory.Instance.CreateEllipseGraphicElement(layout, ellipse, ellipseSym);
  //         elpElm.SetName("New Ellipse");

  var polyLine = PolylineBuilderEx.CreatePolyline(ellipse);
  GraphicElement elpElm = ElementFactory.Instance.CreateGraphicElement(layout, polyLine, ellipseSym, "New Ellipse");
});

//Create curve text with basic text properties.

//Construct on the worker thread
await QueuedTask.Run(() =>
{
  //Build geometry
  Coordinate2D pt1 = new Coordinate2D(3.6, 7.5);
  Coordinate2D pt2 = new Coordinate2D(4.26, 8);
  Coordinate2D pt3 = new Coordinate2D(4.93, 7.1);
  Coordinate2D pt4 = new Coordinate2D(5.6, 7.5);
  //At 2.x - CubicBezierBuilder bez = new CubicBezierBuilder(pt1, pt2, pt3, pt4);
  var bez = new CubicBezierBuilderEx(pt1, pt2, pt3, pt4);
  CubicBezierSegment bezSeg = bez.ToSegment();
  //At 2.x - Polyline bezPl = PolylineBuilder.CreatePolyline(bezSeg);
  Polyline bezPl = PolylineBuilderEx.CreatePolyline(bezSeg);

  //Set symbolology, create and add element to layout
  CIMTextSymbol sym = SymbolFactory.Instance.ConstructTextSymbol(ColorFactory.Instance.BlackRGB, 24, "Comic Sans MS", "Regular");
  //At 2.x - GraphicElement bezTxtElm = LayoutElementFactory.Instance.CreateCurvedTextGraphicElement(layout, bezPl, "Curved Text", sym);
  //         bezTxtElm.SetName("New Splinned Text");
  GraphicElement bezTxtElm = ElementFactory.Instance.CreateTextGraphicElement(
                                layout, TextType.SplinedText, bezPl, sym, "Curved Text", "New Splinned Text");
});

//Must be on QueuedTask.Run(() => { ...

//Build geometry
List<Coordinate2D> plCoords = new List<Coordinate2D>();
plCoords.Add(new Coordinate2D(1.5, 10.5));
plCoords.Add(new Coordinate2D(1.25, 9.5));
plCoords.Add(new Coordinate2D(1, 10.5));
plCoords.Add(new Coordinate2D(0.75, 9.5));
plCoords.Add(new Coordinate2D(0.5, 10.5));
plCoords.Add(new Coordinate2D(0.5, 1));
plCoords.Add(new Coordinate2D(0.75, 2));
plCoords.Add(new Coordinate2D(1, 1));
Polyline linePl = PolylineBuilderEx.CreatePolyline(plCoords);

//Set symbolology, create and add element to layout
CIMLineSymbol lineSym = SymbolFactory.Instance.ConstructLineSymbol(
          ColorFactory.Instance.BlackRGB, 2.0, SimpleLineStyle.Solid);
//var graphic = GraphicFactory.Instance.CreateShapeGraphic(linePl, lineSym);

var ge = ElementFactory.Instance.CreateGraphicElement(
                        container, linePl, lineSym, "New Freehand");

//Must be on QueuedTask.Run(() => { ...

//Build geometry
List<Coordinate2D> plCoords = new List<Coordinate2D>();
plCoords.Add(new Coordinate2D(1, 8.5));
plCoords.Add(new Coordinate2D(1.66, 9));
plCoords.Add(new Coordinate2D(2.33, 8.1));
plCoords.Add(new Coordinate2D(3, 8.5));
Polyline linePl = PolylineBuilderEx.CreatePolyline(plCoords);

//Reference a line symbol in a style
var ProjectStyles = Project.Current.GetItems<StyleProjectItem>();
StyleProjectItem style = ProjectStyles.First(x => x.Name == "ArcGIS 2D");
var symStyle = style.SearchSymbols(StyleItemType.LineSymbol, "Line with 2 Markers")[0];
CIMLineSymbol lineSym = symStyle.Symbol as CIMLineSymbol;
lineSym.SetSize(20);

//Set symbolology, create and add element to layout
//CIMLineSymbol lineSym = SymbolFactory.Instance.ConstructLineSymbol(ColorFactory.Instance.BlueRGB, 4.0, SimpleLineStyle.Solid);
ElementFactory.Instance.CreateGraphicElement(
  container, linePl, lineSym, "New Line");