protected function addHiddenKey(GridContract $grid)
    {
        $fieldsets = $grid->fieldsets();
        if ($fieldsets->isEmpty()) {
            return false;
        }
        $name    = $fieldsets->first()->name;
        $name instanceof Closure and $name    = sprintf('fieldset-%d', $fieldsets->count());
        $slugged = str_slug($name);
        $grid->hidden('key', function($field) use($slugged) {
            $control         = Memory::make('runtime')->get('control');
            $field->value    = $this->hiddenKey = Crypt::encrypt(implode('::', [$control['component'], $control['action'], $control['method'], $slugged]));
            return $field;
        });
        return true;
    }