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.ImmutableMultimap$FieldSettersHolder
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.google.common.collect.ImmutableMultimap$FieldSettersHolder
  super_class: java.lang.Object
{
  static final com.google.common.collect.Serialization$FieldSetter<com.google.common.collect.ImmutableMultimap> MAP_FIELD_SETTER;
    descriptor: Lcom/google/common/collect/Serialization$FieldSetter;
    flags: (0x0018) ACC_STATIC, ACC_FINAL
    Signature: Lcom/google/common/collect/Serialization$FieldSetter<Lcom/google/common/collect/ImmutableMultimap;>;

  static final com.google.common.collect.Serialization$FieldSetter<com.google.common.collect.ImmutableMultimap> SIZE_FIELD_SETTER;
    descriptor: Lcom/google/common/collect/Serialization$FieldSetter;
    flags: (0x0018) ACC_STATIC, ACC_FINAL
    Signature: Lcom/google/common/collect/Serialization$FieldSetter<Lcom/google/common/collect/ImmutableMultimap;>;

  static void <clinit>();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=2, locals=0, args_size=0
         0: .line 340
            ldc Lcom/google/common/collect/ImmutableMultimap;
            ldc "map"
            invokestatic com.google.common.collect.Serialization.getFieldSetter:(Ljava/lang/Class;Ljava/lang/String;)Lcom/google/common/collect/Serialization$FieldSetter;
         1: .line 339
            putstatic com.google.common.collect.ImmutableMultimap$FieldSettersHolder.MAP_FIELD_SETTER:Lcom/google/common/collect/Serialization$FieldSetter;
         2: .line 342
            ldc Lcom/google/common/collect/ImmutableMultimap;
            ldc "size"
            invokestatic com.google.common.collect.Serialization.getFieldSetter:(Ljava/lang/Class;Ljava/lang/String;)Lcom/google/common/collect/Serialization$FieldSetter;
         3: .line 341
            putstatic com.google.common.collect.ImmutableMultimap$FieldSettersHolder.SIZE_FIELD_SETTER:Lcom/google/common/collect/Serialization$FieldSetter;
         4: .line 342
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  void <init>();
    descriptor: ()V
    flags: (0x0000) 
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.google.common.collect.ImmutableMultimap$FieldSettersHolder this
         0: .line 338
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // com.google.common.collect.ImmutableMultimap$FieldSettersHolder this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/common/collect/ImmutableMultimap$FieldSettersHolder;
}
SourceFile: "ImmutableMultimap.java"
NestHost: com.google.common.collect.ImmutableMultimap
InnerClasses:
  FieldSettersHolder = com.google.common.collect.ImmutableMultimap$FieldSettersHolder of com.google.common.collect.ImmutableMultimap
  final FieldSetter = com.google.common.collect.Serialization$FieldSetter of com.google.common.collect.Serialization
    RuntimeInvisibleAnnotations: 
      com.google.common.annotations.GwtIncompatible()