public function normalizeField(IndexField $field)
    {
        $id = $field->getId();
        $value = $field->getValue();

        $log = $this->getLogger();
        $context = array('field' => $id);

        if (isset($this->_fieldTypes[$id])) {
            if ($this->_searchEngine->hasNormalizer($this->_fieldTypes[$id])) {
                $normalizer = $this->_searchEngine->getNormalizer($this->_fieldTypes[$id]);
                $context['normalizer'] = get_class($normalizer);
                $value = $normalizer->normalize($value);
                $log->debug('Normalizer applied to field', $context);
            }
        } else {
            $log->debug('Data type could not be determined for field', $context);
        }

        return $value;
    }