private void _strataLB_SelectedValueChanged(object sender, EventArgs e)
        {
            FieldSetupStratum stratum = _strataLB.SelectedValue as FieldSetupStratum;

            if (stratum == null)
            {
                return;
            }
            HandleFieldSetupSelectedStratumChanged(stratum);
        }
        private void HandleFieldSetupSelectedStratumChanged(FieldSetupStratum stratum)
        {
            if (stratum != null)
            {
                this._treeFieldWidget.SelectedItemsDataSource = stratum.SelectedTreeFields;
                this._treeFieldWidget.DataSource = stratum.UnselectedTreeFields;

                this._logFieldWidget.SelectedItemsDataSource = stratum.SelectedLogFields;
                this._logFieldWidget.DataSource = stratum.UnselectedLogFields;
            }
        }