https://openjdk.java.net/ 
public interface java.awt.desktop.SystemSleepListener extends java.awt.desktop.SystemEventListener
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: java.awt.desktop.SystemSleepListener
  super_class: java.lang.Object
{
  public abstract void systemAboutToSleep(java.awt.desktop.SystemSleepEvent);
    descriptor: (Ljava/awt/desktop/SystemSleepEvent;)V
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
      Name  Flags
      e     

  public abstract void systemAwoke(java.awt.desktop.SystemSleepEvent);
    descriptor: (Ljava/awt/desktop/SystemSleepEvent;)V
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
      Name  Flags
      e     
}
SourceFile: "SystemSleepListener.java"