How to create Dynamo element by Revit API

1

I need to create Dynamo element by Revit API and c#.
I think the code should like
using DG = Autodesk.DesignScript.Geometry;
DG.Point startPoint = DG.Point.ByCoordinates(0, 0, 0);
DG.Point endPoint = DG.Point.ByCoordinates(10, 0, 0);
DG.Line line = DG.Line.ByStartPointEndPoint(startPoint, endPoint);
But I dont know how to show the line in Dynamo.
I really need help.