How to set the costumcontextsearch field names translateable

static $searchable_fields = array(
      'Elamutyyp' => 'ExactMatchFilter',
      'Hind' => 'ExactMatchFilter',
      'Tubadearv' => 'ExactMatchFilter',
      'Yldpind' => 'ExactMatchFilter',
      'Linn' => 'ExactMatchFilter',
      );

   static $summary_fields = array(
      'Elamutyyp',
      'Hind',
      'Tubadearv',
      'Yldpind',
      'Linn'
      );

function getCustomSearchContext() {
      $fields = $this->scaffoldSearchFields(array (
         'restrictFields' => array (
         'Elamutyyp' => 'Elamutyyp',
         'Hind' => 'Hind',
         'Tubadearv'=>'Tubadearv',
         'Yldpind'=>'Yldpind',
         'Linn'=>'Linn'
)
));
$filters = array (
'Elamutyyp' => new ExactMatchFilter('Elamutyyp'),
'Hind' => new ExactMatchFilter('Hind'),
'Tubadearv' => new ExactMatchFilter('Tubadearv'),
'Yldpind' => new ExactMatchFilter('Yldpind'),
'Linn' => new ExactMatchFilter('Linn')
);
return new SearchContext($this->class, $fields, $filters); }