docs: def _login(self, username, password):
          '''Authenticates a TissueMAPS user.
  
          Parameters
          ----------
          username: str
              name
          password: str
              password
          '''
          logger.debug('login in as user "%s"' % username)
          url = self._build_url('/auth')
          payload = {'username': username, 'password': password}
          res = self._session.post(url, json=payload)
          res.raise_for_status()
          self._access_token = res.json()['access_token']
          self._session.headers.update(
              {'Authorization': 'JWT %s' % self._access_token}
          )