[Pharo-project] roelTyper doesn't always return assignements

Hi, I'm trying to use RoelTyper in Pharo. A question I ask myself is: 'Is it normal that roelTyper doesn't always return some assignements' ? For example, when I evaluate: TypeCollector typeInstvar: #array ofClass: OrderedCollection . the assignements returned is an empty collection. I would expect that even roelTyper doesn't retrieve the exact type, it would always return a collection of 'candidate' types. Am I using it in a wrong way?