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.handler.codec.http.websocketx.extensions.WebSocketExtension
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: io.netty.handler.codec.http.websocketx.extensions.WebSocketExtension
  super_class: java.lang.Object
{
  public static final int RSV1;
    descriptor: I
    flags: (0x0019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL
    ConstantValue: 4

  public static final int RSV2;
    descriptor: I
    flags: (0x0019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL
    ConstantValue: 2

  public static final int RSV3;
    descriptor: I
    flags: (0x0019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL
    ConstantValue: 1

  public abstract int rsv();
    descriptor: ()I
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT

  public abstract io.netty.handler.codec.http.websocketx.extensions.WebSocketExtensionEncoder newExtensionEncoder();
    descriptor: ()Lio/netty/handler/codec/http/websocketx/extensions/WebSocketExtensionEncoder;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT

  public abstract io.netty.handler.codec.http.websocketx.extensions.WebSocketExtensionDecoder newExtensionDecoder();
    descriptor: ()Lio/netty/handler/codec/http/websocketx/extensions/WebSocketExtensionDecoder;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
}
SourceFile: "WebSocketExtension.java"