What's a better way to test if a block is passed on?

ugly_spec.rb

it "should pass along blocks if given" do
  class Baz3
    def initialize(attributes = nil, &block)
      yield if block_given?
    end
  end

  class Qiz3 < Baz3
    include Eventable
  end
  @cheesy = nil
  Qiz3.new() { @cheesy = "but it works" }
  @cheesy.should == "but it works"
end

I'm testing that my library can accept a block and passes it along properly. My library doesn't actually use a block but it needs to support a class that inherits from a class that does.

Since my library doesn't actually use a block I need to fabricate a situation where one is used to test that I pass it along properly.