https://openjdk.java.net/ 
interface sun.security.ssl.NamedGroupCredentials extends sun.security.ssl.SSLCredentials
  minor version: 0
  major version: 59
  flags: flags: (0x0600) ACC_INTERFACE, ACC_ABSTRACT
  this_class: sun.security.ssl.NamedGroupCredentials
  super_class: java.lang.Object
{
  public abstract java.security.PublicKey getPublicKey();
    descriptor: ()Ljava/security/PublicKey;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT

  public abstract sun.security.ssl.NamedGroup getNamedGroup();
    descriptor: ()Lsun/security/ssl/NamedGroup;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
}
SourceFile: "NamedGroupCredentials.java"