public function createBaseString()
    {
        if ($this->timestamp === 0) {
            $this->setTimestamp();
        }

        $paramArray = array(
            'oauth_nonce' => $this->getNonce(),
            'oauth_callback' => $this->callback,
            'oauth_signature_method' => $this->signatureMethod,
            'oauth_timestamp' => $this->getTimestamp(),
            'oauth_consumer_key' => $this->consumerCredential->getIdentifier(),
            'oauth_token' => $this->userCredential->getIdentifier(),
            'oauth_version' => $this->version,
            'oauth_verifier' => $this->getVerifier()
        );

        return $this->buildBaseString($paramArray);
    }