Calling function from another script works but gameobjects instances are not loaded why?

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
namespace UnityEngine.ProBuilder.Experimental.CSG
{
    public class Subtractoperation : MonoBehaviour
    {

        public GameObject rodtomake;
        public GameObject tool;
        private Mesh result;
        GameObject composite;
        public void executemyoperation()
        {

            Debug.Log("do subtraction");
            result = CSG.Subtract(rodtomake, tool);

            composite = new GameObject();
            composite.AddComponent<MeshFilter>().sharedMesh = result;
            composite.AddComponent<MeshRenderer>().enabled = result;
            Destroy(rodtomake);
            Destroy(tool);
        }
    }

}

Subtractoperation d = new Subtractoperation();
d.executemyoperation();