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.util.AttributeMap
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: io.netty.util.AttributeMap
  super_class: java.lang.Object
{
  public abstract <T> io.netty.util.Attribute<T> attr(io.netty.util.AttributeKey<T>);
    descriptor: (Lio/netty/util/AttributeKey;)Lio/netty/util/Attribute;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Signature: <T:Ljava/lang/Object;>(Lio/netty/util/AttributeKey<TT;>;)Lio/netty/util/Attribute<TT;>;
    MethodParameters:
      Name  Flags
      key   

  public abstract <T> boolean hasAttr(io.netty.util.AttributeKey<T>);
    descriptor: (Lio/netty/util/AttributeKey;)Z
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Signature: <T:Ljava/lang/Object;>(Lio/netty/util/AttributeKey<TT;>;)Z
    MethodParameters:
      Name  Flags
      key   
}
SourceFile: "AttributeMap.java"