code: def get_authorize_url(self, redirect_uri=None, **kw):
          '''
          return the authorization url that the user should be redirected to.
          '''
          redirect = redirect_uri if redirect_uri else self.redirect_uri
          if not redirect:
              raise APIError('21305', 'Parameter absent: redirect_uri', 'OAuth2 request')
          response_type = kw.pop('response_type', 'code')
          return '%s%s?%s' % (self.auth_url, 'authorize',
                              _encode_params(client_id=self.client_id,
                                             response_type=response_type,
                                             redirect_uri=redirect, **kw)f get_authorize_url(self, redirect_uri=None, **kw):
          '''
          return the authorization url that the user should be redirected to.
          '''
          redirect = redirect_uri if redirect_uri else self.redirect_uri
          if not redirect:
              raise APIError('21305', 'Parameter absent: redirect_uri', 'OAuth2 request')
          response_type = kw.pop('response_type', 'code')
          return '%s%s?%s' % (self.auth_url, 'authorize',
                              _encode_params(client_id=self.client_id,
                                             response_type=response_type,
                                             redirect_uri=redirect, **kw))
docs: return the authorization url that the user should be redirected to.