https://openjdk.java.net/ 
public interface sun.awt.WindowClosingListener
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: sun.awt.WindowClosingListener
  super_class: java.lang.Object
{
  public abstract java.lang.RuntimeException windowClosingNotify(java.awt.event.WindowEvent);
    descriptor: (Ljava/awt/event/WindowEvent;)Ljava/lang/RuntimeException;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
       Name  Flags
      event  

  public abstract java.lang.RuntimeException windowClosingDelivered(java.awt.event.WindowEvent);
    descriptor: (Ljava/awt/event/WindowEvent;)Ljava/lang/RuntimeException;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
       Name  Flags
      event  
}
SourceFile: "WindowClosingListener.java"