PenLineJoin

 using cAlgo.API;
 namespace cAlgo
 {
     // This sample shows how to use a shape Stroke Line Join
     [Indicator(IsOverlay = true, TimeZone = TimeZones.UTC, AccessRights = AccessRights.None)]
     public class PenLineJoinSample : Indicator
     {
         [Parameter("Stroke Line Join", DefaultValue = PenLineJoin.Miter)]
         public PenLineJoin StrokeLineJoin { get; set; }
         protected override void Initialize()
         {
             var rectangle = new Rectangle
             {
                 HorizontalAlignment = HorizontalAlignment.Center,
                 VerticalAlignment = VerticalAlignment.Center,
                 StrokeLineJoin = StrokeLineJoin,
                 StrokeColor = Color.Red,
                 StrokeThickness = 4,
                 Width = 200,
                 Height = 100,
             };
             Chart.AddControl(rectangle);
         }
         public override void Calculate(int index)
         {
         }
     }
 }

 import clr
 clr.AddReference("cAlgo.API")
 from cAlgo.API import *
 class Test():    
     def initialize(self):
         rectangle = Rectangle()
         rectangle.HorizontalAlignment = HorizontalAlignment.Center
         rectangle.VerticalAlignment = VerticalAlignment.Center
         # StrokeLineJoin is a parameter of type StrokeLineJoin defined
         # in indicator C# file
         rectangle.StrokeLineJoin = api.StrokeLineJoin
         rectangle.StrokeColor = Color.Red
         rectangle.StrokeThickness = 4
         rectangle.Width = 200
         rectangle.Height = 100
         api.Chart.AddControl(rectangle)