Does away with this pesky compiler warning in scala 2.10.0 "`withFilter' method does not yet exist on org.json4s.JValue, using `filter' method instead"

JValueWithFilter.scala

import org.json4s.JValue
implicit class LiftJValueWithFilter(self: JValue)
       extends JValueWithFilter(self, _ => true)

class JValueWithFilter(self: JValue, p: JValue => Boolean) {
  def map(f: JValue => T): List[T] = 
    self.filter(p).map(f)
  def flatMap(f: JValue => List[T]): List[T] =
    self.filter(p).flatMap(f)
  def foreach(f: JValue => Unit): Unit =
    self.filter(p).foreach(f)
  def withFilter(q: JValue => Boolean): JValueWithFilter =
    new JValueWithFilter(self, x => p(x) && q(x))
}

Thanks a lot! Obvious, but so useful!