Quick does not instantiate new objects for each test

Mutator.swift

class Mutator {
    var mutated: Bool
    init() {
        mutated = false
    }

    func mutate() {
        mutated = true
    }
}

WantItToWorkTest.swift

// Please note that this style does not work, but I'd like it to!
// Apple's built-in unit testing framework allows for this. How?
//   Answer: They instatiate a new test object for each test

class MyQuickTest: QuickSpec {
    override func spec() {

        describe("Mutator") {
            let subject = Mutator()

            it("test 1") {
                expect(subject.mutated).to(beFalse())
                subject.mutate()
                expect(subject.mutated).to(beTrue())
            }

            it("test 2") {
                expect(subject.mutated).to(beFalse()) // currently fails because `subject` is same mutated object from "test 1"
                subject.mutate()
                expect(subject.mutated).to(beTrue())
            }
        }
    }
}

WorkingTest.swift

// undesirables:
//   1. must declare shared variable as "var" and not "let"
//   2. must use `beforeEach` to instantiate before each test run
//   3. must use "!" (or worse `if let`) to access underlying value since it's now an optional

class MyQuickTest: QuickSpec {
    override func spec() {

        describe("Mutator") {
            var subject: Mutator?
            beforeEach {
                subject = Mutator()
            }

            it("test 1") {
                expect(subject!.mutated).to(beFalse())
                subject!.mutate()
                expect(subject!.mutated).to(beTrue())
            }

            it("test 2") {
                expect(subject!.mutated).to(beFalse())
                subject!.mutate()
                expect(subject!.mutated).to(beTrue())
            }
        }
    }
}