How can I create a RuleSet with a .NET FluentValidation InlineValidator?

I'm creating an InlineValidator (from the FluentValidation nuget package/library).

var validator = new InlineValidator<Person>;validator.RuleFor(x => x.Surname).NotNull();validator.RuleSet("someRuleSet", () => {    // ?????            });

When I try to call the RuleSet method in there, it seems to not compile.

How can I create a RuleSet against an InlineValidator please ?

Here's the example ruleset i'm trying...

.RuleSet("someRuleSet", () =>{    RuleFor(x => x.Name).NotNull();    RuleFor(x => x.Age).NotEqual(0);}