private function addSearchFields(Fieldset $fieldset)
    {
        $fieldset->addField(
            'search_weight',
            'select',
            [
                'name' => 'search_weight',
                'label' => __('Search Weight'),
                'values' => $this->weightSource->getOptions(),
            ],
            'is_searchable'
        );

        $fieldset->addField(
            'is_used_in_spellcheck',
            'select',
            [
                'name'   => 'is_used_in_spellcheck',
                'label'  => __('Used in spellcheck'),
                'values' => $this->booleanSource->toOptionArray(),
            ],
            'search_weight'
        );

        return $this;
    }