protected function key()
    {
        $key = rawurlencode($this->clientCredentials->getSecret()).'&';

        if ($this->credentials !== null) {
            $key .= rawurlencode($this->credentials->getSecret());
        }

        return $key;
    }
protected function key()
    {
        $key = rawurlencode($this->clientCredentials->getSecret()).'&';

        if ($this->credentials !== null) {
            $key .= rawurlencode($this->credentials->getSecret());
        }

        return $key;
    }
protected function key ( ) { $ key = rawurlencode ( $ this -> clientCredentials -> getSecret ( ) ) . '&' ; if ( $ this -> credentials !== null ) { $ key .= rawurlencode ( $ this -> credentials -> getSecret ( ) ) ; } return $ key ; }
Generate a signing key.

@return string
Generate a signing key .