https://openjdk.java.net/ 
public interface com.sun.security.jgss.ExtendedGSSCredential extends org.ietf.jgss.GSSCredential
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: com.sun.security.jgss.ExtendedGSSCredential
  super_class: java.lang.Object
{
  public abstract org.ietf.jgss.GSSCredential impersonate(org.ietf.jgss.GSSName);
    descriptor: (Lorg/ietf/jgss/GSSName;)Lorg/ietf/jgss/GSSCredential;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Exceptions:
      throws org.ietf.jgss.GSSException
    MethodParameters:
      Name  Flags
      name  
}
SourceFile: "ExtendedGSSCredential.java"