How to initialize a variable dynamically in Xtend 2 -

this i've written in xtend class:

    def getentitylist(string indct, string criterion) {     var entities     switch(indct){     case "par": entities = obj.getparamlist.filter[definition.contains(criterion)]     case "ref": entities = obj.getreflist.filter[definition.contains(criterion)]     default: entities = null     } return entities } 

as in above code, entities raw list type initialization of i'm trying based on condition. depending on condition entities list either have parameters or references. think not straight forward in perl xtend statically-typed language.

how achieve above in xtend 2?

var entities = switch(indct) {   case 'par': obj.getparamlist.filter[definition.contains(criterion)]   case 'ref': obj.getreflist.filter[definition.contains(criterion)] } 

entities have type list<? extends "common super type of param , ref">. asking for?