Get and order biggest tuples from list - scala

Question

I'm trying to order my list and get the biggest 5 tuples in my list which will then be printed out, heres the code that i have been working with:
import scala.io.Codec.string2codec
import scala.io.Source
import scala.reflect.io.File
import org.apache.spark.SparkContext
import org.apache.spark.SparkContext._
import org.apache.spark.SparkConf
object SimpleWordCount {
def main(args: Array[String]) {
val conf = new SparkConf().setAppName("Simple Word Count")
val sc = new SparkContext(conf)
val test = scala.io.Source.fromFile("/home/cloudera/Books/book1.txt").getLines
val wordCount =
test
.flatMap(_.split("\\W+"))
.foldLeft(Map.empty[String, Int]) {
(count, word) =>
count + (word -> (count.getOrElse(word, 0) + 1))
}
val formatteWordCount =
filtered
.map(tuple => s"${tuple._1} -> ${tuple._2}")
.mkString("\n", "\n", "\n")
when trying to launch the code the following lines gives the error:
diverging implicit expansion for type scala.math.Ordering[B]
starting with method Tuple9 in object Ordering
.sortBy(x => (x._2))
I also tried using .stableSort(k, (x, y) => x._2 < y.2) which gave the error value stableSort is not a member of String
and .maxBy(._2) which gave the error diverging implicit expansion for type Ordering[B]
starting with method Tuple9 in object Ordering
println(s"Final Word Count: $formatteWordCount")
}