docs: def login(self):
          """Authorize client."""
          if not self.auth.access_token or \
                  (hasattr(self.auth, 'access_token_expired') and self.auth.access_token_expired):
              import httplib2
  
              http = httplib2.Http()
              self.auth.refresh(http)
  
          self.session.headers.update({
              'Authorization': 'Bearer %s' % self.auth.access_token
          })