public function convertFilter($value, $sourceUnit, $destinationUnit, $unitName, $locale = null)
	{
		if (null !== $value) {
			$translatedUnitName = $this->translator->trans($unitName, array(), 'SasedevExtraToolsBundle');

			$value = $this->converter->convert($value, $sourceUnit, $destinationUnit, $locale);
			$value = $value . ' ' . $translatedUnitName;
		}

		return $value;
	}