Coverage on mapping with tuples does not seem to work

[cowboygneox]

In this example:

object TestObject {                                 
    def stuff(): Unit = {                           
        val set = Set(1, 2, 3)                      

        val (a, b, c) = set.toSeq.zipWithIndex.map {
          case (z, i) =>                            
            (z + 1, z + 2, z + 3)                   
        }.unzip3                                    
    }                                               

    stuff()                                         
}

The following does not seem to get any overage at all:

        val (a, b, c) = set.toSeq.zipWithIndex.map {
          case (z, i) =>                            
            (z + 1, z + 2, z + 3)                   
        }.unzip3

I tried to create a test, but I couldn't figure it out.