Yup, in your method signature you simply have one last parameter called &bl and then bl is set to the Proc object. You can no longer call yield(...) but instea

Yup, in your method signature you simply have one last parameter called &bl and then bl is set to the Proc object. You can no longer call yield(...) but instead you have to use bl.call(...) You can indeed save the Proc object and use it later.