https://openjdk.java.net/ 
public interface sun.awt.RequestFocusController
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: sun.awt.RequestFocusController
  super_class: java.lang.Object
{
  public abstract boolean acceptRequestFocus(java.awt.Component, java.awt.Component, boolean, boolean, java.awt.event.FocusEvent$Cause);
    descriptor: (Ljava/awt/Component;Ljava/awt/Component;ZZLjava/awt/event/FocusEvent$Cause;)Z
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
                            Name  Flags
      from                        
      to                          
      temporary                   
      focusedWindowChangeAllowed  
      cause                       
}
SourceFile: "RequestFocusController.java"
InnerClasses:
  public final Cause = java.awt.event.FocusEvent$Cause of java.awt.event.FocusEvent