http://www.bouncycastle.org/java.html: The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains JCE provider and lightweight API for the Bouncy Castle Cryptography APIs for JDK 1.5. 
public class org.bouncycastle.asn1.DERNull extends org.bouncycastle.asn1.ASN1Null
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: org.bouncycastle.asn1.DERNull
  super_class: org.bouncycastle.asn1.ASN1Null
{
  public static final org.bouncycastle.asn1.DERNull INSTANCE;
    descriptor: Lorg/bouncycastle/asn1/DERNull;
    flags: (0x0019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL

  byte[] zeroBytes;
    descriptor: [B
    flags: (0x0000) 

  static void <clinit>();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=2, locals=0, args_size=0
         0: .line 11
            new org.bouncycastle.asn1.DERNull
            dup
            invokespecial org.bouncycastle.asn1.DERNull.<init>:()V
            putstatic org.bouncycastle.asn1.DERNull.INSTANCE:Lorg/bouncycastle/asn1/DERNull;
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // org.bouncycastle.asn1.DERNull this
         0: .line 15
            aload 0 /* this */
            invokespecial org.bouncycastle.asn1.ASN1Null.<init>:()V
         1: .line 13
            aload 0 /* this */
            iconst_0
            newarray 8
            putfield org.bouncycastle.asn1.DERNull.zeroBytes:[B
         2: .line 17
            return
        end local 0 // org.bouncycastle.asn1.DERNull this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lorg/bouncycastle/asn1/DERNull;

  void encode(org.bouncycastle.asn1.DEROutputStream);
    descriptor: (Lorg/bouncycastle/asn1/DEROutputStream;)V
    flags: (0x0000) 
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // org.bouncycastle.asn1.DERNull this
        start local 1 // org.bouncycastle.asn1.DEROutputStream out
         0: .line 23
            aload 1 /* out */
            iconst_5
            aload 0 /* this */
            getfield org.bouncycastle.asn1.DERNull.zeroBytes:[B
            invokevirtual org.bouncycastle.asn1.DEROutputStream.writeEncoded:(I[B)V
         1: .line 24
            return
        end local 1 // org.bouncycastle.asn1.DEROutputStream out
        end local 0 // org.bouncycastle.asn1.DERNull this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lorg/bouncycastle/asn1/DERNull;
            0    2     1   out  Lorg/bouncycastle/asn1/DEROutputStream;
    Exceptions:
      throws java.io.IOException
    MethodParameters:
      Name  Flags
      out   
}
SourceFile: "DERNull.java"