public function buildBaseString(array $oauthParams)
    {
        $tempArray = array();
        ksort($oauthParams);

        if ($oauthParams['oauth_callback'] === '') {
            unset($oauthParams['oauth_callback']);
        }

        if ($oauthParams['oauth_verifier'] === '') {
            unset($oauthParams['oauth_verifier']);
        }

        array_walk($oauthParams, function($value, $key) use (&$tempArray) {
            $tempArray[] = $key . '=' . rawurlencode($value);
        });

        $parsedUrl = parse_url($this->resourceURL);
        $baseString = $this->httpMethod .'&';
        $baseString .= rawurlencode($parsedUrl['scheme'] . '://' . $parsedUrl['host'] . $parsedUrl['path']);
        $baseString .= (isset($parsedUrl['query'])) ? '&' . rawurlencode($parsedUrl['query']) . '%26' : '&';
        $baseString .= rawurlencode(implode('&', $tempArray));

        array_walk($this->postFields, function($value, $key) use (&$baseString) {
            $baseString .= '%26' . $key . rawurlencode('=' . $value);
        });

        return $baseString;
    }