src/http/Http.php
static public function addParams($url, $params)
    {
        $query = parse_url($url, PHP_URL_QUERY);
        $separator = (Text::isEmpty($query)? "?" : "&");
        return Text::concat($separator, $url, http_build_query($params));
    }
static public function addParams($url, $params)
    {
        $query = parse_url($url, PHP_URL_QUERY);
        $separator = (Text::isEmpty($query)? "?" : "&");
        return Text::concat($separator, $url, http_build_query($params));
    }
Appends parameters to a given url.

For example:
```php
echo Http::addParams("http://www.mysite.php", array("username" => "John", "id" => 101));
```

@param string $url    URL
@param array  $params Associative array of parameters

@return strings.