https://openjdk.java.net/ 
public interface java.security.PrivateKey extends java.security.Key, javax.security.auth.Destroyable
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: java.security.PrivateKey
  super_class: java.lang.Object
{
  public static final long serialVersionUID;
    descriptor: J
    flags: (0x0019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL
    ConstantValue: 6034044314589513430
}
SourceFile: "PrivateKey.java"