InheritenceExample.scala

trait Trackable {
    def setOffset(value: Long): Unit
  }

  trait Gauge {
    def set(off: Long): Unit
  }

  val gauge: Gauge = ???
  val counter: AtomicLong = ???

  case class TrackableGauage() extends Gauge with Trackable {
    override def set(off: Long): Unit = ??? /* Gauge impel of set method */

    override def setOffset(value: Long): Unit = this.set(value)
  }

  case class TrackableAtomicLong() extends AtomicLong with Trackable {
    override def setOffset(value: Long): Unit = this.set(value)
  }

  def offsetMonitor[F[_]: Functor, E, H[_]: Functor, T](monitor: H[Trackable]) = {
    Flow[EnvT[E, F, ProducerResult[T]]].map { elem =>
      elem.map { e =>
        monitor.map { m =>
          m.setOffset(e.env.offset)
        }
      }

      elem
    }
  }
}