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.Grain128$Mappings extends java.util.HashMap
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: org.bouncycastle.jce.provider.symmetric.Grain128$Mappings
  super_class: java.util.HashMap
{
  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // org.bouncycastle.jce.provider.symmetric.Grain128$Mappings this
         0: .line 37
            aload 0 /* this */
            invokespecial java.util.HashMap.<init>:()V
         1: .line 39
            aload 0 /* this */
            ldc "Cipher.Grain128"
            ldc "org.bouncycastle.jce.provider.symmetric.Grain128$Base"
            invokevirtual org.bouncycastle.jce.provider.symmetric.Grain128$Mappings.put:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
            pop
         2: .line 40
            aload 0 /* this */
            ldc "KeyGenerator.Grain128"
            ldc "org.bouncycastle.jce.provider.symmetric.Grain128$KeyGen"
            invokevirtual org.bouncycastle.jce.provider.symmetric.Grain128$Mappings.put:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
            pop
         3: .line 41
            return
        end local 0 // org.bouncycastle.jce.provider.symmetric.Grain128$Mappings this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    4     0  this  Lorg/bouncycastle/jce/provider/symmetric/Grain128$Mappings;
}
SourceFile: "Grain128.java"
NestHost: org.bouncycastle.jce.provider.symmetric.Grain128
InnerClasses:
  public Mappings = org.bouncycastle.jce.provider.symmetric.Grain128$Mappings of org.bouncycastle.jce.provider.symmetric.Grain128