Example of unsafe secondary publication in Java

class SafePublsiher {
  private static volatile SafePublsiher p = null;
  public static SafePublsiher get() {
    // initialization block
    return p;
  }
}

class UnSafePublisher {
  private static SafePublisher p = null;
  public static SafePusblisher get() {
    if (p == null) { p = SafePublisher.get() }
    return p;
  }
}