1 step to working

FractalTreeGtk/Draw/Branch.cs

@@ -0,0 +1,13 @@
+using System.Numerics;
+
+namespace FractalTreeGtk.Draw
+{
+    internal class Branch : CairoObjective.DrawObjects.Line
+    {
+        public bool left;
+        public Branch(double x1, double y1, double x2, double y2, bool left) : base(x1, y1, x2, y2)
+        {
+            this.left = left;
+        }
+    }
+}