https://www.graalvm.org/ 
abstract class com.oracle.truffle.polyglot.PolyglotMap$Cache$EntrySet extends com.oracle.truffle.polyglot.PolyglotMap$Cache$PolyglotMapNode
  minor version: 0
  major version: 59
  flags: flags: (0x0420) ACC_SUPER, ACC_ABSTRACT
  this_class: com.oracle.truffle.polyglot.PolyglotMap$Cache$EntrySet
  super_class: com.oracle.truffle.polyglot.PolyglotMap$Cache$PolyglotMapNode
{
  void <init>(com.oracle.truffle.polyglot.PolyglotMap$Cache);
    descriptor: (Lcom/oracle/truffle/polyglot/PolyglotMap$Cache;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.oracle.truffle.polyglot.PolyglotMap$Cache$EntrySet this
        start local 1 // com.oracle.truffle.polyglot.PolyglotMap$Cache cache
         0: .line 505
            aload 0 /* this */
            aload 1 /* cache */
            invokespecial com.oracle.truffle.polyglot.PolyglotMap$Cache$PolyglotMapNode.<init>:(Lcom/oracle/truffle/polyglot/PolyglotMap$Cache;)V
         1: .line 506
            return
        end local 1 // com.oracle.truffle.polyglot.PolyglotMap$Cache cache
        end local 0 // com.oracle.truffle.polyglot.PolyglotMap$Cache$EntrySet this
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    2     0   this  Lcom/oracle/truffle/polyglot/PolyglotMap$Cache$EntrySet;
            0    2     1  cache  Lcom/oracle/truffle/polyglot/PolyglotMap$Cache;
    MethodParameters:
       Name  Flags
      cache  

  protected java.lang.Object doCached(com.oracle.truffle.polyglot.PolyglotLanguageContext, java.lang.Object, java.lang.Object[], com.oracle.truffle.api.interop.InteropLibrary, com.oracle.truffle.polyglot.ToHostNode, com.oracle.truffle.api.profiles.BranchProfile);
    descriptor: (Lcom/oracle/truffle/polyglot/PolyglotLanguageContext;Ljava/lang/Object;[Ljava/lang/Object;Lcom/oracle/truffle/api/interop/InteropLibrary;Lcom/oracle/truffle/polyglot/ToHostNode;Lcom/oracle/truffle/api/profiles/BranchProfile;)Ljava/lang/Object;
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=7, locals=13, args_size=7
        start local 0 // com.oracle.truffle.polyglot.PolyglotMap$Cache$EntrySet this
        start local 1 // com.oracle.truffle.polyglot.PolyglotLanguageContext languageContext
        start local 2 // java.lang.Object receiver
        start local 3 // java.lang.Object[] args
        start local 4 // com.oracle.truffle.api.interop.InteropLibrary interop
        start local 5 // com.oracle.truffle.polyglot.ToHostNode toHost
        start local 6 // com.oracle.truffle.api.profiles.BranchProfile error
         0: .line 514
            aconst_null
            astore 7 /* keys */
        start local 7 // java.util.List keys
         1: .line 515
            iconst_0
            istore 8 /* keysSize */
        start local 8 // int keysSize
         2: .line 516
            lconst_0
            lstore 9 /* elemSize */
        start local 9 // long elemSize
         3: .line 517
            aload 3 /* args */
            iconst_2
            aaload
            checkcast com.oracle.truffle.polyglot.PolyglotMap
            astore 11 /* originalMap */
        start local 11 // com.oracle.truffle.polyglot.PolyglotMap originalMap
         4: .line 519
            aload 0 /* this */
            getfield com.oracle.truffle.polyglot.PolyglotMap$Cache$EntrySet.cache:Lcom/oracle/truffle/polyglot/PolyglotMap$Cache;
            getfield com.oracle.truffle.polyglot.PolyglotMap$Cache.memberKey:Z
            ifeq 13
            aload 4 /* interop */
            aload 2 /* receiver */
            invokevirtual com.oracle.truffle.api.interop.InteropLibrary.hasMembers:(Ljava/lang/Object;)Z
            ifeq 13
         5: .line 522
            aload 4 /* interop */
            aload 2 /* receiver */
            invokevirtual com.oracle.truffle.api.interop.InteropLibrary.getMembers:(Ljava/lang/Object;)Ljava/lang/Object;
            astore 12 /* truffleKeys */
        start local 12 // java.lang.Object truffleKeys
         6: .line 523
            goto 10
        end local 12 // java.lang.Object truffleKeys
      StackMap locals: com.oracle.truffle.polyglot.PolyglotMap$Cache$EntrySet com.oracle.truffle.polyglot.PolyglotLanguageContext java.lang.Object java.lang.Object[] com.oracle.truffle.api.interop.InteropLibrary com.oracle.truffle.polyglot.ToHostNode com.oracle.truffle.api.profiles.BranchProfile java.util.List int long com.oracle.truffle.polyglot.PolyglotMap
      StackMap stack: com.oracle.truffle.api.interop.UnsupportedMessageException
         7: pop
         8: .line 524
            aload 6 /* error */
            invokevirtual com.oracle.truffle.api.profiles.BranchProfile.enter:()V
         9: .line 525
            invokestatic java.util.Collections.emptySet:()Ljava/util/Set;
            areturn
        start local 12 // java.lang.Object truffleKeys
        10: .line 527
      StackMap locals: java.lang.Object
      StackMap stack:
            aload 1 /* languageContext */
            aload 12 /* truffleKeys */
            iconst_0
            ldc Ljava/lang/String;
            aconst_null
            invokestatic com.oracle.truffle.polyglot.PolyglotList.create:(Lcom/oracle/truffle/polyglot/PolyglotLanguageContext;Ljava/lang/Object;ZLjava/lang/Class;Ljava/lang/reflect/Type;)Ljava/util/List;
            astore 7 /* keys */
        11: .line 528
            aload 7 /* keys */
            invokeinterface java.util.List.size:()I
            istore 8 /* keysSize */
        end local 12 // java.lang.Object truffleKeys
        12: .line 529
            goto 19
      StackMap locals:
      StackMap stack:
        13: aload 0 /* this */
            getfield com.oracle.truffle.polyglot.PolyglotMap$Cache$EntrySet.cache:Lcom/oracle/truffle/polyglot/PolyglotMap$Cache;
            getfield com.oracle.truffle.polyglot.PolyglotMap$Cache.numberKey:Z
            ifeq 19
            aload 4 /* interop */
            aload 2 /* receiver */
            invokevirtual com.oracle.truffle.api.interop.InteropLibrary.hasArrayElements:(Ljava/lang/Object;)Z
            ifeq 19
        14: .line 531
            aload 4 /* interop */
            aload 2 /* receiver */
            invokevirtual com.oracle.truffle.api.interop.InteropLibrary.getArraySize:(Ljava/lang/Object;)J
            lstore 9 /* elemSize */
        15: .line 532
            goto 19
      StackMap locals:
      StackMap stack: com.oracle.truffle.api.interop.UnsupportedMessageException
        16: pop
        17: .line 533
            aload 6 /* error */
            invokevirtual com.oracle.truffle.api.profiles.BranchProfile.enter:()V
        18: .line 534
            lconst_0
            lstore 9 /* elemSize */
        19: .line 537
      StackMap locals:
      StackMap stack:
            new com.oracle.truffle.polyglot.PolyglotMap$LazyEntries
            dup
            aload 11 /* originalMap */
            dup
            invokevirtual java.lang.Object.getClass:()Ljava/lang/Class;
            pop
            aload 7 /* keys */
            iload 8 /* keysSize */
            lload 9 /* elemSize */
            l2i
            invokespecial com.oracle.truffle.polyglot.PolyglotMap$LazyEntries.<init>:(Lcom/oracle/truffle/polyglot/PolyglotMap;Ljava/util/List;II)V
            areturn
        end local 11 // com.oracle.truffle.polyglot.PolyglotMap originalMap
        end local 9 // long elemSize
        end local 8 // int keysSize
        end local 7 // java.util.List keys
        end local 6 // com.oracle.truffle.api.profiles.BranchProfile error
        end local 5 // com.oracle.truffle.polyglot.ToHostNode toHost
        end local 4 // com.oracle.truffle.api.interop.InteropLibrary interop
        end local 3 // java.lang.Object[] args
        end local 2 // java.lang.Object receiver
        end local 1 // com.oracle.truffle.polyglot.PolyglotLanguageContext languageContext
        end local 0 // com.oracle.truffle.polyglot.PolyglotMap$Cache$EntrySet this
      LocalVariableTable:
        Start  End  Slot             Name  Signature
            0   20     0             this  Lcom/oracle/truffle/polyglot/PolyglotMap$Cache$EntrySet;
            0   20     1  languageContext  Lcom/oracle/truffle/polyglot/PolyglotLanguageContext;
            0   20     2         receiver  Ljava/lang/Object;
            0   20     3             args  [Ljava/lang/Object;
            0   20     4          interop  Lcom/oracle/truffle/api/interop/InteropLibrary;
            0   20     5           toHost  Lcom/oracle/truffle/polyglot/ToHostNode;
            0   20     6            error  Lcom/oracle/truffle/api/profiles/BranchProfile;
            1   20     7             keys  Ljava/util/List<*>;
            2   20     8         keysSize  I
            3   20     9         elemSize  J
            4   20    11      originalMap  Lcom/oracle/truffle/polyglot/PolyglotMap<Ljava/lang/Object;Ljava/lang/Object;>;
            6    7    12      truffleKeys  Ljava/lang/Object;
           10   12    12      truffleKeys  Ljava/lang/Object;
      Exception table:
        from    to  target  type
           5     6       7  Class com.oracle.truffle.api.interop.UnsupportedMessageException
          14    15      16  Class com.oracle.truffle.api.interop.UnsupportedMessageException
    RuntimeVisibleAnnotations: 
      com.oracle.truffle.api.dsl.Specialization(limit = "LIMIT")
    RuntimeInvisibleParameterAnnotations: 
      0:
      1:
      2:
      3:
        com.oracle.truffle.api.library.CachedLibrary(value = "receiver")
      4:
        com.oracle.truffle.api.dsl.Cached()
      5:
        com.oracle.truffle.api.dsl.Cached()
    MethodParameters:
                 Name  Flags
      languageContext  
      receiver         
      args             
      interop          
      toHost           
      error            

  protected java.lang.String getOperationName();
    descriptor: ()Ljava/lang/String;
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.oracle.truffle.polyglot.PolyglotMap$Cache$EntrySet this
         0: .line 542
            ldc "entrySet"
            areturn
        end local 0 // com.oracle.truffle.polyglot.PolyglotMap$Cache$EntrySet this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/polyglot/PolyglotMap$Cache$EntrySet;
}
SourceFile: "PolyglotMap.java"
NestHost: com.oracle.truffle.polyglot.PolyglotMap
InnerClasses:
  final Cache = com.oracle.truffle.polyglot.PolyglotMap$Cache of com.oracle.truffle.polyglot.PolyglotMap
  abstract EntrySet = com.oracle.truffle.polyglot.PolyglotMap$Cache$EntrySet of com.oracle.truffle.polyglot.PolyglotMap$Cache
  abstract PolyglotMapNode = com.oracle.truffle.polyglot.PolyglotMap$Cache$PolyglotMapNode of com.oracle.truffle.polyglot.PolyglotMap$Cache
  private final LazyEntries = com.oracle.truffle.polyglot.PolyglotMap$LazyEntries of com.oracle.truffle.polyglot.PolyglotMap