scala.Predef.refArrayOps[Reader.this.CoNLLToken](tokens).indices.foreach[scala.collection.mutable.Iterable[_ >: (Int, Int, String) with Int] with scala.collection.AbstractIterable[Any] with scala.collection.mutable.Cloneable[scala.collection.mutable.Iterable[_ >: (Int, Int, String) with Int] with scala.collection.mutable.Cloneable[scala.collection.mutable.Iterable[_ >: (Int, Int, String) with Int] with scala.collection.mutable.Cloneable[Cloneable with Mutable with Equals] with Int => Any{def seq: Cloneable with Mutable with Equals}] with Int => Any] with scala.collection.mutable.Builder[(Int, Int, String) with Int,Iterable[Any] with Int => Any{def seq: Iterable[Any] with Int => Any}] with Int => Any with Serializable with scala.collection.generic.Shrinkable[(Int, Int, String) with Int] with scala.collection.generic.Subtractable[_ >: (Int, Int, String) with Int, Iterable[Any] with Int => Any with scala.collection.generic.Subtractable[_ >: (Int, Int, String) with Int, Iterable[Any] with Int => Any with scala.collection.generic.Subtractable[_ >: (Int, Int, String) with Int, Equals]]{def seq: Iterable[Any] with Int => Any}] with scala.collection.script.Scriptable[_ >: (Int, Int, String) with Int]](((modifier: Int) => {
        val head: Int = tokens.apply(modifier).dep._1;
        if (head.>=(0))
          edges.+=(new (Int, Int, String)(head, modifier, tokens.apply(modifier).dep._2))
        else
          roots.+=(modifier)
      }));

case class Country(name: String)

object Countries {
  def find(name: String): Option[Country] = None
}

import scala.collection.mutable

object Main extends App {

  val data: Seq[(String, String)] = Nil

  val invalid = mutable.Set[String]()
  val countries = mutable.ListBuffer[Country]()

  data.foreach { case (label, code) =>
    Countries.find(code) match {
      case None => invalid
      case Some(c) => countries
    }
  }

}

[error] /web/foo/Main.scala:16: type arguments [?,Iterable[java.io.Serializable] with String with Int => Any with scala.collection.generic.Subtractable[_ >: String with Country <: java.io.Serializable, Iterable[java.io.Serializable] with String with Int => Any with scala.collection.generic.Subtractable[_ >: String with Country <: java.io.Serializable, Equals]]{def seq: Iterable[java.io.Serializable] with String with Int => Any}] do not conform to trait Subtractable's type parameter bounds [A,+Repr <: scala.collection.generic.Subtractable[A,Repr]]
[error]   data.foreach { case (label, code) =>
[error]        ^
[error] one error found
[error] (compile:compileIncremental) Compilation failed
[error] Total time: 5 s, completed Jul 27, 2017 4:06:22 PM