OAuthSimple::_normalizedParameters PHP Method

    private function _normalizedParameters()
    {
        $normalized_keys = array();
        $return_array = array();
        foreach ($this->_parameters as $paramName => $paramValue) {
            if (preg_match('/w+_secret/', $paramName) or $paramName == "oauth_signature") {
                continue;
            }
            // Read parameters from a file. Hope you're practicing safe PHP.
            if (strpos($paramValue, '@') !== 0 && !file_exists(substr($paramValue, 1))) {
                if (is_array($paramValue)) {
                    $normalized_keys[self::_oauthEscape($paramName)] = array();
                    foreach ($paramValue as $item) {
                        array_push($normalized_keys[self::_oauthEscape($paramName)], self::_oauthEscape($item));
                    }
                } else {
                    $normalized_keys[self::_oauthEscape($paramName)] = self::_oauthEscape($paramValue);
                }
            }
        }
        ksort($normalized_keys);
        foreach ($normalized_keys as $key => $val) {
            if (is_array($val)) {
                sort($val);
                foreach ($val as $element) {
                    array_push($return_array, $key . "=" . $element);
                }
            } else {
                array_push($return_array, $key . '=' . $val);
            }
        }
        $presig = join("&", $return_array);
        $sig = urlencode($this->_generateSignature($presig));
        $this->_parameters['oauth_signature'] = $sig;
        array_push($return_array, "oauth_signature={$sig}");
        return join("&", $return_array);
    }