private void referenceToolStripMenuItem_Click(object sender, EventArgs e)
 {
     using (var picker = new ResourcePicker(_edSvc.CurrentConnection, ResourceTypes.SymbolDefinition.ToString(), ResourcePickerMode.OpenResource))
     {
         if (picker.ShowDialog() == DialogResult.OK)
         {
             LastSelectedFolder.FolderId = picker.SelectedFolder;
             var symRef = _comp.CreateSymbolReference(picker.ResourceID);
             AddInstance(symRef, true);
         }
     }
 }