code: def check_token(self, token=None):
          
          if token is None:
              token = self.token
          resp, resp_body = self.method_head("tokens/%s" % token, admin=True)
          if resp.status_code in (401, 403):
              raise exc.AuthorizationFailure("You must be an admin to make this "
                      "call.")
          return 200 <= resp.status_code < 300
docs: ADMIN ONLY. Returns True or False, depending on whether the current
          token is valid.