public function addCondition(Filter $filter, $attribute, $partial = false)
    {
        $value = $this->$attribute;

        if (mb_strpos($value, '>') !== false) {
            $value = (int)str_replace('>', '', $value);
            $filter->addMatcher($attribute, new matchers\GreaterThan(['value' => $value]));

        } elseif (mb_strpos($value, '<') !== false) {
            $value = (int)str_replace('<', '', $value);
            $filter->addMatcher($attribute, new matchers\LowerThan(['value' => $value]));
        } else {
            $filter->addMatcher($attribute, new matchers\SameAs(['value' => $value, 'partial' => $partial]));
        }
    }