Scala compiling error: Cannot resolve overloaded method 'withTransaction'

I’m new to Scala, and I can’t figure out how to solve a compiling error for method withTransaction :

Cannot resolve overloaded method 'withTransaction'

  override def onGet() {
    JPA.withTransaction(() => {
      val resultsList = JPA.em.createNamedQuery("findCity").setParameter("name", name).getResultList

This code snippet is located in a Global.scala file in Play project (version 2.3.X). JPA came from import play.db.jpa.JPA

How can I solve this compiling error?