http://www.jboss.org/undertow-parent/undertow-core: Undertow (JBoss by Red Hat) 
public interface io.undertow.client.ClientCallback<T>
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: io.undertow.client.ClientCallback
  super_class: java.lang.Object
{
  public abstract void completed();
    descriptor: (Ljava/lang/Object;)V
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Signature: (TT;)V
    MethodParameters:
        Name  Flags
      result  

  public abstract void failed(java.io.IOException);
    descriptor: (Ljava/io/IOException;)V
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
      Name  Flags
      e     
}
Signature: <T:Ljava/lang/Object;>Ljava/lang/Object;
SourceFile: "ClientCallback.java"