Title is not entirely accurate, but the point is that currently the CriteriaTriggers for advancements has a private REGISTRY and register() method.  Without being able to register a new ICriterionTrigger object with this registry, modders cannot create new advacement triggers (this includes recipes that award on something other than the vanilla triggers).  For example, I want to create a trigger that will test true when any one of a list of items is picked up (the vanilla InventoryChanged trigge