Get Most Frequent Strings from List[String]

most-frequent.scala

// get most frequent Strings from the newest n values
def mostFrequent(l:List[String], n:Int): List[String] = {
      val id = l.take(Math.min(list.length, i)).unzip._1.groupBy(identity)
      val frq = id.maxBy(_._2.size)._2.size
      id.filter(_._2.size == frq)
}