https://openjdk.java.net/ 
public interface java.security.cert.X509Extension
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: java.security.cert.X509Extension
  super_class: java.lang.Object
{
  public abstract boolean hasUnsupportedCriticalExtension();
    descriptor: ()Z
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT

  public abstract java.util.Set<java.lang.String> getCriticalExtensionOIDs();
    descriptor: ()Ljava/util/Set;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Signature: ()Ljava/util/Set<Ljava/lang/String;>;

  public abstract java.util.Set<java.lang.String> getNonCriticalExtensionOIDs();
    descriptor: ()Ljava/util/Set;
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Signature: ()Ljava/util/Set<Ljava/lang/String;>;

  public abstract byte[] getExtensionValue(java.lang.String);
    descriptor: (Ljava/lang/String;)[B
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
      Name  Flags
      oid   
}
SourceFile: "X509Extension.java"