Is exist Interface or Base class for Custom setting? I tried use SObject class, but it does not support Custom Settings Methods.

Is exist Interface or Base class for Custom setting? I tried use SObject class, but it does not support Custom Settings Methods.

For any SObject we can use SObject class, that base class for standard and custom object.

SObject account = new Account();

We can use SObject for Custom Settings, but there are no specific Custom Setting methods

SObject settings = new MyCustomSettings__c();

What class contains specific Custom Settings methods?