private function registerFields()
    {
        $this->app->singleton( FieldTypeRegistry::class, function ( Application $app )
        {
            $fieldTypeRegistry = new FieldTypeRegistry();

            $fieldTypeRegistry->registerByType( 'integer', Hidden::class, 'int' );
            $fieldTypeRegistry->registerByType( 'string', Text::class, 'string' );
            $fieldTypeRegistry->registerByType( 'text', Textarea::class, 'string' );
            $fieldTypeRegistry->registerByType( 'longtext', Richtext::class, 'string' );
            $fieldTypeRegistry->registerByType( 'datetime', DateTime::class, 'string' );
            $fieldTypeRegistry->registerByType( 'boolean', Checkbox::class, 'bool' );

            $fieldTypeRegistry->registerByRelation( 'file', ArboryFile::class );
            $fieldTypeRegistry->registerByRelation( 'image', ArboryImage::class );
            $fieldTypeRegistry->registerByRelation( 'link', Link::class );

            return $fieldTypeRegistry;
        } );
    }