protected function _wildcards($value)
    {
        if (!is_string($value)) {
            return false;
        }

        $value = $this->_formatWildcards($value);
        if ($this->getConfig('before')) {
            $value = $this->_formatWildcards($this->getConfig('wildcardAny')) . $value;
        }

        if ($this->getConfig('after')) {
            $value = $value . $this->_formatWildcards($this->getConfig('wildcardAny'));
        }

        return $value;
    }