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 abstract class io.netty.channel.AbstractEventLoopGroup extends io.netty.util.concurrent.AbstractEventExecutorGroup implements io.netty.channel.EventLoopGroup
  minor version: 0
  major version: 59
  flags: flags: (0x0421) ACC_PUBLIC, ACC_SUPER, ACC_ABSTRACT
  this_class: io.netty.channel.AbstractEventLoopGroup
  super_class: io.netty.util.concurrent.AbstractEventExecutorGroup
{
  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // io.netty.channel.AbstractEventLoopGroup this
         0: .line 24
            aload 0 /* this */
            invokespecial io.netty.util.concurrent.AbstractEventExecutorGroup.<init>:()V
            return
        end local 0 // io.netty.channel.AbstractEventLoopGroup this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lio/netty/channel/AbstractEventLoopGroup;

  public abstract io.netty.channel.EventLoop next();
    descriptor: ()Lio/netty/channel/EventLoop;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT

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