add playground code

Program.cs

@@ -0,0 +1,41 @@
+using System;
+using CSiAPIv1;
+
+namespace CSiAPIPlayground
+{
+  class Program
+  {
+    private const string ProgID_SAP2000 = "CSI.SAP2000.API.SapObject";
+    private const string ProgID_ETABS = "CSI.ETABS.API.ETABSObject";
+    private const string ProgID_CSiBridge = "CSI.CSiBridge.API.SapObject";
+    private const string ProgID_SAFE = "CSI.SAFE.API.SAFEObject";
+
+    static void Main(string[] _)
+    {
+      var apiObj = GetActiveAPIObject(new Helper());
+      var playground = new Playground(apiObj.SapModel);
+      playground.Play();
+    }
+
+    private static cOAPI GetActiveAPIObject(Helper helper)
+    {
+      if (helper.GetObject(ProgID_ETABS) is cOAPI etabsModel)
+      {
+        return etabsModel;
+      }
+      else if (helper.GetObject(ProgID_SAP2000) is cOAPI sapModel)
+      {
+        return sapModel;
+      }
+      else if (helper.GetObject(ProgID_SAFE) is cOAPI safeModel)
+      {
+        return safeModel;
+      }
+      else if (helper.GetObject(ProgID_CSiBridge) is cOAPI bridgeModel)
+      {
+        return bridgeModel;
+      }
+      throw new Exception("Unable to find running instance of csi application :(");
+    }
+  }
+}