protected function collectNormalBelongsToRelationAccessors()
    {
        $accessors = [];

        foreach ($this->data['relationships']['normal'] as $name => $relationship) {
            if ($relationship['type'] != Generator::RELATIONSHIP_BELONGS_TO) continue;
            if ( ! empty($relationship['key']) && snake_case($name) !== $relationship['key']) continue;

            $attributeName = snake_case($name);

            $content = $this->tab(2) . "return \$this->getBelongsToRelationAttributeValue('{$name}');\n";

            $accessors[ $name ] = [
                'attribute' => $attributeName,
                'content'   => $content,
            ];
        }

        return $accessors;
    }