library/Rediska/Command/GetRandomKey.php
public function parseResponse($response)
    {
        if ($response == '') {
            return null;
        } else {
            if ($this->_rediska->getOption('namespace') != '' && strpos($response, $this->_rediska->getOption('namespace')) === 0) {
                $response = substr($response, strlen($this->_rediska->getOption('namespace')));
            }

            return $response;
        }
    }
public function parseResponse($response)
    {
        if ($response == '') {
            return null;
        } else {
            if ($this->_rediska->getOption('namespace') != '' && strpos($response, $this->_rediska->getOption('namespace')) === 0) {
                $response = substr($response, strlen($this->_rediska->getOption('namespace')));
            }

            return $response;
        }
    }
Parse response

@param string $response
@return string|null