code: function determineClientScope (req, res, next) {
    var params = req.connectParams
    var subject = req.client
    var scope = params.scope || subject.default_client_scope
  
    if (params.grant_type === 'client_credentials') {
      Scope.determine(scope, subject, function (err, scope, scopes) {
        if (err) { return next(err) }
        req.scope = scope
        req.scopes = scopes
        next()
      })
    } else {
      next()
    }
  }
docs: Determine client scope