List<AuthScope> allowedScopes

The list of scopes available when authorizing with this client.

Scoping is determined by this instance; i.e. the authorizing client determines which scopes a token has. This list contains all valid scopes for this client. If null, client does not support scopes and all access tokens have same authorization.

Source 

List<AuthScope> get allowedScopes => _allowedScopes;
void allowedScopes=(List<AuthScope> scopes)

Source 

set allowedScopes(List<AuthScope> scopes) {
  _allowedScopes = scopes
    ?.where((s) {
      return !scopes.any((otherScope) =>
        s.isSubsetOrEqualTo(otherScope) && !s.isExactlyScope(otherScope));
      })
      ?.toList();
}