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.jce.provider.symmetric.RC5$Mac32 extends org.bouncycastle.jce.provider.JCEMac
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: org.bouncycastle.jce.provider.symmetric.RC5$Mac32
  super_class: org.bouncycastle.jce.provider.JCEMac
{
  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=5, locals=1, args_size=1
        start local 0 // org.bouncycastle.jce.provider.symmetric.RC5$Mac32 this
         0: .line 127
            aload 0 /* this */
            new org.bouncycastle.crypto.macs.CBCBlockCipherMac
            dup
            new org.bouncycastle.crypto.engines.RC532Engine
            dup
            invokespecial org.bouncycastle.crypto.engines.RC532Engine.<init>:()V
            invokespecial org.bouncycastle.crypto.macs.CBCBlockCipherMac.<init>:(Lorg/bouncycastle/crypto/BlockCipher;)V
            invokespecial org.bouncycastle.jce.provider.JCEMac.<init>:(Lorg/bouncycastle/crypto/Mac;)V
         1: .line 128
            return
        end local 0 // org.bouncycastle.jce.provider.symmetric.RC5$Mac32 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lorg/bouncycastle/jce/provider/symmetric/RC5$Mac32;
}
SourceFile: "RC5.java"
NestHost: org.bouncycastle.jce.provider.symmetric.RC5
InnerClasses:
  public Mac32 = org.bouncycastle.jce.provider.symmetric.RC5$Mac32 of org.bouncycastle.jce.provider.symmetric.RC5