https://github.com/google/guava/guava: Guava is a suite of core and expanded libraries that include utility classes, google's collections, io classes, and much much more. 
class com.google.common.collect.RegularImmutableBiMap$InverseSerializedForm<K, V> implements java.io.Serializable
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.google.common.collect.RegularImmutableBiMap$InverseSerializedForm
  super_class: java.lang.Object
{
  private final com.google.common.collect.ImmutableBiMap<K, V> forward;
    descriptor: Lcom/google/common/collect/ImmutableBiMap;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Lcom/google/common/collect/ImmutableBiMap<TK;TV;>;

  private static final long serialVersionUID;
    descriptor: J
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    ConstantValue: 1

  void <init>(com.google.common.collect.ImmutableBiMap<K, V>);
    descriptor: (Lcom/google/common/collect/ImmutableBiMap;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.google.common.collect.RegularImmutableBiMap$InverseSerializedForm this
        start local 1 // com.google.common.collect.ImmutableBiMap forward
         0: .line 295
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 296
            aload 0 /* this */
            aload 1 /* forward */
            putfield com.google.common.collect.RegularImmutableBiMap$InverseSerializedForm.forward:Lcom/google/common/collect/ImmutableBiMap;
         2: .line 297
            return
        end local 1 // com.google.common.collect.ImmutableBiMap forward
        end local 0 // com.google.common.collect.RegularImmutableBiMap$InverseSerializedForm this
      LocalVariableTable:
        Start  End  Slot     Name  Signature
            0    3     0     this  Lcom/google/common/collect/RegularImmutableBiMap$InverseSerializedForm<TK;TV;>;
            0    3     1  forward  Lcom/google/common/collect/ImmutableBiMap<TK;TV;>;
    Signature: (Lcom/google/common/collect/ImmutableBiMap<TK;TV;>;)V
    MethodParameters:
         Name  Flags
      forward  

  java.lang.Object readResolve();
    descriptor: ()Ljava/lang/Object;
    flags: (0x0000) 
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.google.common.collect.RegularImmutableBiMap$InverseSerializedForm this
         0: .line 300
            aload 0 /* this */
            getfield com.google.common.collect.RegularImmutableBiMap$InverseSerializedForm.forward:Lcom/google/common/collect/ImmutableBiMap;
            invokevirtual com.google.common.collect.ImmutableBiMap.inverse:()Lcom/google/common/collect/ImmutableBiMap;
            areturn
        end local 0 // com.google.common.collect.RegularImmutableBiMap$InverseSerializedForm this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/common/collect/RegularImmutableBiMap$InverseSerializedForm<TK;TV;>;
}
Signature: <K:Ljava/lang/Object;V:Ljava/lang/Object;>Ljava/lang/Object;Ljava/io/Serializable;
SourceFile: "RegularImmutableBiMap.java"
NestHost: com.google.common.collect.RegularImmutableBiMap
InnerClasses:
  private InverseSerializedForm = com.google.common.collect.RegularImmutableBiMap$InverseSerializedForm of com.google.common.collect.RegularImmutableBiMap