Need to implement Litium.ComponentModel.IReadOnly

Hello, I’m trying to prepopulate a custom product field, its really just a string array, But I can’t get it to work.
The normal TextOptions works fine, but not my custom class:

is there a collection I can use? that already implements Litium.ComponentModel.IReadOnly and make this possible? Or do I need to use the TextOption class/Create a custom class?

                     IReadOnlyCollection<FieldData> options = getOptions();

                    var clone = fieldDefinition.MakeWritableClone();
                    clone.Option = options;

                    using (_securityContextService.ActAsSystem())
                    {               
                       _fieldDefinitionService.Update(clone);
                    }

Error:
Litium.Validations.ValidationException: 'Validation error for FieldDefinition(SystemId: e40b95a4-c6a1-4ef7-2478-08d65529a601, Id: Ingredients), Option: 'The 'System.Collections.Generic.List`1[[System.String, mscorlib]], mscorlib' need to implement Litium.ComponentModel.IReadOnly.'.'

Litium version: 7

The ‘options’ that are assigned on the field definition need to be a class that implement ‘IReadOnly’ interface on the same way as the ‘TextOption’. You custom options should then be stored in a property on this class.