http://netty.io/netty-all/: Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers and clients. (The Netty Project) 
public interface io.netty.channel.ChannelFutureListener extends io.netty.util.concurrent.GenericFutureListener<io.netty.channel.ChannelFuture>
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: io.netty.channel.ChannelFutureListener
  super_class: java.lang.Object
{
  public static final io.netty.channel.ChannelFutureListener CLOSE;
    descriptor: Lio/netty/channel/ChannelFutureListener;
    flags: (0x0019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL

  public static final io.netty.channel.ChannelFutureListener CLOSE_ON_FAILURE;
    descriptor: Lio/netty/channel/ChannelFutureListener;
    flags: (0x0019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL

  public static final io.netty.channel.ChannelFutureListener FIRE_EXCEPTION_ON_FAILURE;
    descriptor: Lio/netty/channel/ChannelFutureListener;
    flags: (0x0019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL

  static void <clinit>();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=2, locals=0, args_size=0
         0: .line 41
            new io.netty.channel.ChannelFutureListener$1
            dup
            invokespecial io.netty.channel.ChannelFutureListener$1.<init>:()V
            putstatic io.netty.channel.ChannelFutureListener.CLOSE:Lio/netty/channel/ChannelFutureListener;
         1: .line 52
            new io.netty.channel.ChannelFutureListener$2
            dup
            invokespecial io.netty.channel.ChannelFutureListener$2.<init>:()V
            putstatic io.netty.channel.ChannelFutureListener.CLOSE_ON_FAILURE:Lio/netty/channel/ChannelFutureListener;
         2: .line 65
            new io.netty.channel.ChannelFutureListener$3
            dup
            invokespecial io.netty.channel.ChannelFutureListener$3.<init>:()V
            putstatic io.netty.channel.ChannelFutureListener.FIRE_EXCEPTION_ON_FAILURE:Lio/netty/channel/ChannelFutureListener;
         3: .line 72
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature
}
Signature: Ljava/lang/Object;Lio/netty/util/concurrent/GenericFutureListener<Lio/netty/channel/ChannelFuture;>;
SourceFile: "ChannelFutureListener.java"
NestMembers:
  io.netty.channel.ChannelFutureListener$1  io.netty.channel.ChannelFutureListener$2  io.netty.channel.ChannelFutureListener$3
InnerClasses:
  io.netty.channel.ChannelFutureListener$1
  io.netty.channel.ChannelFutureListener$2
  io.netty.channel.ChannelFutureListener$3