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. 
abstract class com.google.common.collect.BaseImmutableMultimap<K, V> extends com.google.common.collect.AbstractMultimap<K, V>
  minor version: 0
  major version: 59
  flags: flags: (0x0420) ACC_SUPER, ACC_ABSTRACT
  this_class: com.google.common.collect.BaseImmutableMultimap
  super_class: com.google.common.collect.AbstractMultimap
{
  void <init>();
    descriptor: ()V
    flags: (0x0000) 
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.google.common.collect.BaseImmutableMultimap this
         0: .line 25
            aload 0 /* this */
            invokespecial com.google.common.collect.AbstractMultimap.<init>:()V
            return
        end local 0 // com.google.common.collect.BaseImmutableMultimap this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/common/collect/BaseImmutableMultimap<TK;TV;>;
}
Signature: <K:Ljava/lang/Object;V:Ljava/lang/Object;>Lcom/google/common/collect/AbstractMultimap<TK;TV;>;
SourceFile: "BaseImmutableMultimap.java"
    RuntimeInvisibleAnnotations: 
      com.google.common.annotations.GwtCompatible()