ocaml-batteries-team/batteries-included — pull request #467 by jpdeplaix (2013-11-21 13:26:55+00:00)
Title: Add List.{is_contained_in,image}

I don't know if it's the good way to name those functions. If you have a better idea, I'll be glad to hear it.
I also don't know if the choice of not putting an optional parameter to image in Labels in good or not.