'This is a "constructor" for the URL class.
:param scheme: http/https
:param netloc: domain and port
:param path: directory
:param params: URL params
:param qs: query string
:param fragment: #fragments
:return: An instance of URL.'

@classmethod
def from_parts(cls, scheme, netloc, path, params, qs, fragment, encoding=DEFAULT_ENCODING):

    scheme = (scheme or u'')
    netloc = (netloc or u'')
    path = (path or u'')
    params = (params or u'')
    qs = (qs or u'')
    fragment = (fragment or u'')
    data = (scheme, netloc, path, params, qs, fragment)
    url_str = urlparse.urlunparse(data)
    return cls(url_str, encoding)
