I havea collection of radio program schedule objects which includes title and broadcast date.

(title, date)is unique, but title is not, because radio shows can be repeated. I
just need a list with the title and the last broadcast date.

What is the Smalltalk way of creating a new collection where title is unique? I know
how to do this in procedural code, but I expect that there is a more elegant, OO way.

OrderedCollection

Dr Who  1/1/14
Dr Who  1/2/14
Dr Who  1/3/14

Result 
Dr Who  1/3/14

Thanks,
jrm