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.EventLoop extends io.netty.util.concurrent.OrderedEventExecutor, io.netty.channel.EventLoopGroup
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: io.netty.channel.EventLoop
  super_class: java.lang.Object
{
  public abstract io.netty.channel.EventLoopGroup parent();
    descriptor: ()Lio/netty/channel/EventLoopGroup;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT

  public io.netty.util.concurrent.EventExecutorGroup parent();
    descriptor: ()Lio/netty/util/concurrent/EventExecutorGroup;
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=1, locals=1, args_size=1
         0: .line 1
            aload 0
            invokeinterface io.netty.channel.EventLoop.parent:()Lio/netty/channel/EventLoopGroup;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
}
SourceFile: "EventLoop.java"