Surrounding property was added

StructureHelperLogics/NdmCalculations/Primitives/IHasSurroundingPrimitive.cs

@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace StructureHelperLogics.NdmCalculations.Primitives
+{
+    public interface IHasSurroundingPrimitive
+    {
+        INdmPrimitive? SurroundingPrimitive { get; set; }
+    }
+}