internal void Refresh(TreeViewItem item)
        {
            Tracer.Verbose("DatabaseExplorerService:Refresh", "START");

            try
            {
                SchemaObjectBase dbObject = (SchemaObjectBase)item.Tag;

                if (dbObject != null)
                {
                    dbObject.Refresh();

                    item.IsExpanded = false;
                    item.Items.Clear();
                    this.treeViewDB.AddDummyItem(item);
                }
            }
            catch (Exception err)
            {
                Tracer.Error("DatabaseExplorerService.Refresh", err);
            }
            finally
            {
                Tracer.Verbose("DatabaseExplorerService:Refresh", "END");
            }
        }