private void BtnDeleteObjectsClick1(object sender, EventArgs e)
        {
            IExpression query = BuildExpression(out var dataTypeName);

            treeNavigation.BeginUpdate();
            if (chkProp1.Checked && (chkProp2.Checked || chkProp3.Checked || chkProp4.Checked || chkPropItemName.Checked))
            {
                // at least 1 query clause selected - continue)
                _loggerRef.Target.LogDebug("DELETEing all [{0}] objects where: {1}", dataTypeName, query.DisplayString());
                _client.DebugRequests = chkDebugRequests.Checked;
                _client.DeleteUntypedObjects(dataTypeName, query);
                ClearTree();
            }
            else
            {
                _loggerRef.Target.LogDebug("DELETE ignored - DataTypeName and 1 other query clause must be selected");
            }
            treeNavigation.EndUpdate();
            chkDebugRequests.Checked = false;
        }