code: def _validate_token(self, token, scopes_required=None):
          
          if scopes_required is None:
              scopes_required = []
          scopes_required = set(scopes_required)
  
          token_info = None
          valid_token = False
          has_required_scopes = False
          if token:
              try:
                  token_info = self._get_token_info(token)
              except Exception as ex:
                  token_info = {'active': False}
                  logger.error('ERROR: Unable to get token info')
                  logger.error(str(ex))
  
              valid_token = token_info.get('active', False)
  
              if 'aud' in token_info and \
                      current_app.config['OIDC_RESOURCE_CHECK_AUD']:
                  valid_audience = False
                  aud = token_info['aud']
                  clid = self.client_secrets['client_id']
                  if isinstance(aud, list):
                      valid_audience = clid in aud
                  else:
                      valid_audience = clid == aud
  
                  if not valid_audience:
                      logger.error('Refused token because of invalid '
                                   'audience')
                      valid_token = False
  
              if valid_token:
                  token_scopes = token_info.get('scope', '').split(' ')
              else:
                  token_scopes = []
              has_required_scopes = scopes_required.issubset(
                  set(token_scopes))
  
              if not has_required_scopes:
                  logger.debug('Token missed required scopes')
  
          if (valid_token and has_required_scopes):
              g.oidc_token_info = token_info
              return True
  
          if not valid_token:
              return 'Token required but invalid'
          elif not has_required_scopes:
              return 'Token does not have required scopes'
          else:
              return 'Something went wrong checking your token'
docs: The actual implementation of validate_token.