private void EventHandlerCore_ObjectSelected(object sender, BimPlusEventArgs e)
        {
            Debug.WriteLine(string.Format("Id:{0} Selected:{1} Multiselect:{2}", e.Id, e.Selected, e.Multiselect));

            if (e.Id != Guid.Empty || e.Selected != true)
            {
                DtObject dtObject = _integrationBase.ApiCore.DtObjects.GetObject(e.Id, ObjectRequestProperties.AttributDefinition | ObjectRequestProperties.Pset);

                if (dtObject != null)
                {
                    if (e.Multiselect == true)
                    {
                        if (SelectedObjects.FirstOrDefault(o => o.Id == e.Id) == null)
                        {
                            SelectedObjects.Add(dtObject);
                        }
                    }
                    else
                    {
                        SelectedObjects.Clear();
                        if (e.Selected == true)
                        {
                            SelectedObjects.Add(dtObject);
                        }
                    }
                }

                if (e.Selected == false)
                {
                    DtObject exist = SelectedObjects.FirstOrDefault(o => o.Id == e.Id);
                    if (exist != null)
                    {
                        SelectedObjects.Remove(exist);
                    }
                    else
                    {
                        SelectedObjects.Clear();
                    }
                }
                else if (e.Selected == null && e.Id != Guid.Empty)
                {
                    if (dtObject != null)
                    {
                        if (SelectedObjects.FirstOrDefault(o => o.Id == e.Id) == null)
                        {
                            SelectedObjects.Add(dtObject);
                        }
                    }
                    else
                    {
                        SelectedObjects.Clear();
                    }
                }

                List <DtObject> newList = new List <DtObject>();
                newList.AddRange(SelectedObjects);
                SelectedObjects = newList;
                Trace.WriteLine(string.Format("_selectedObjects.Count:{0}", SelectedObjects.Count()));
            }
        }