We have no real replacement - but there is a widespread opinion that the renderer will be "burned to the ground" so we should be cautious about how much protoComponent material we oblige our users to use. There's also an issue with this function in that it is not declarative - part of the reason behind the original "optionsToLabelMap" code was to enable a straightforward use of "protoTree" as a component option which would be more desirable than writing this function. If it wasn't for the direct reference to options material in the style of "that.options.strings.themes" there would be no problem making this usage declarative. We need to think about reasonable compromise answers to these questions quite soon since anything we write here will almost immediately become a prototype for reimplementation or copy-pasting by our clients.