private void _ok_Click(object sender, EventArgs e)
 {
     if (Enum.TryParse <SecurityControlType>((string)_controlType.SelectedItem, out var controlType))
     {
         _mitigation             = _threatModel.AddMitigation(_name.Text);
         _mitigation.Description = _description.Text;
         _mitigation.ControlType = controlType;
     }
 }