public void OnGUI()
    {
        EditorGUILayout.BeginVertical();

        EditorGUILayout.BeginHorizontal();
        EditorGUILayout.LabelField("Number");
        number = EditorGUILayout.IntField(number);
        EditorGUILayout.EndHorizontal();

        EditorGUILayout.BeginHorizontal();
        EditorGUILayout.LabelField("Activated");
        activated = EditorGUILayout.Toggle(activated);
        EditorGUILayout.EndHorizontal();

        EditorGUILayout.BeginHorizontal();
        EditorGUILayout.LabelField("Parent");
        parent = (ObjectContainerScript)EditorGUILayout.ObjectField(parent, typeof(ObjectContainerScript), true);
        EditorGUILayout.EndHorizontal();

        EditorGUILayout.BeginHorizontal();
        EditorGUILayout.LabelField("GameObject");
        gameobject = (GameObject)EditorGUILayout.ObjectField(gameobject, typeof(GameObject), false);
        EditorGUILayout.EndHorizontal();

        if (GUILayout.Button("Generate multiple object"))
        {
            parent.initializeChildrenList();
            for (int i = 0; i < number; i++)
            {
                var go = (GameObject)PrefabUtility.InstantiatePrefab(gameobject);
                go.transform.position = new Vector3(0, 0, i);
                go.SetActive(activated);
                parent.AddChildren(go);
                Undo.RegisterCreatedObjectUndo(go, "MultipleGO");

            }
        }

        EditorGUILayout.EndVertical();
    }