trait Auditable {
  boolean audit() {
    if (check()) { // showing as unknown (underlined)
      ;
    }
  }
  private boolean check() {
    true
  }
}

trait Auditable {
  boolean audit() {
    if (check()) { // showing as unknown (underlined)
      ;
    }
  }
  private static boolean check() {
    true
  }
}

trait Auditable extends Checkable {
  boolean audit() {
    if (check()) { // showing as unknown (underlined)
      ;
    }
  }
}
trait Checkable {
  static boolean check() {
    true
  }
}