Yes I can see it is quite common, but having looked carefully
through the tutorials, I haven't been able to find where
this specific task is demonstrated (how to use a hash as a
property of an object and how to write a method to retrieve
the key/value pairs). No doubt it is easy once you know
how (and understand what is going on), but I'm buggered (as
they say in Australia) if I can work it out ....