https://www.graalvm.org/ 
class com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1 implements java.util.Iterator<java.lang.String>
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1
  super_class: java.lang.Object
{
  int index;
    descriptor: I
    flags: (0x0000) 

  final com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet this$2;
    descriptor: Lcom/oracle/truffle/polyglot/PolyglotValue$InteropValue$MemberSet;
    flags: (0x1010) ACC_FINAL, ACC_SYNTHETIC

  void <init>(com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet);
    descriptor: (Lcom/oracle/truffle/polyglot/PolyglotValue$InteropValue$MemberSet;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1 this
         0: .line 3197
            aload 0 /* this */
            aload 1
            putfield com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1.this$2:Lcom/oracle/truffle/polyglot/PolyglotValue$InteropValue$MemberSet;
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 3199
            aload 0 /* this */
            iconst_0
            putfield com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1.index:I
         2: .line 3197
            return
        end local 0 // com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lcom/oracle/truffle/polyglot/PolyglotValue$InteropValue$MemberSet$1;
    MethodParameters:
        Name  Flags
      this$0  final

  public boolean hasNext();
    descriptor: ()Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1 this
         0: .line 3202
            aload 0 /* this */
            getfield com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1.index:I
            aload 0 /* this */
            getfield com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1.this$2:Lcom/oracle/truffle/polyglot/PolyglotValue$InteropValue$MemberSet;
            invokevirtual com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet.size:()I
            if_icmpge 1
            iconst_1
            ireturn
      StackMap locals:
      StackMap stack:
         1: iconst_0
            ireturn
        end local 0 // com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lcom/oracle/truffle/polyglot/PolyglotValue$InteropValue$MemberSet$1;

  public java.lang.String next();
    descriptor: ()Ljava/lang/String;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=5, locals=2, args_size=1
        start local 0 // com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1 this
         0: .line 3206
            aload 0 /* this */
            getfield com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1.index:I
            aload 0 /* this */
            getfield com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1.this$2:Lcom/oracle/truffle/polyglot/PolyglotValue$InteropValue$MemberSet;
            invokevirtual com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet.size:()I
            if_icmplt 2
         1: .line 3207
            new java.util.NoSuchElementException
            dup
            invokespecial java.util.NoSuchElementException.<init>:()V
            athrow
         2: .line 3209
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1.this$2:Lcom/oracle/truffle/polyglot/PolyglotValue$InteropValue$MemberSet;
            getfield com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet.keys:Lorg/graalvm/polyglot/Value;
            aload 0 /* this */
            dup
            getfield com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1.index:I
            dup_x1
            iconst_1
            iadd
            putfield com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1.index:I
            i2l
            invokevirtual org.graalvm.polyglot.Value.getArrayElement:(J)Lorg/graalvm/polyglot/Value;
            astore 1 /* arrayElement */
        start local 1 // org.graalvm.polyglot.Value arrayElement
         3: .line 3210
            aload 1 /* arrayElement */
            invokevirtual org.graalvm.polyglot.Value.isString:()Z
            ifeq 5
         4: .line 3211
            aload 1 /* arrayElement */
            invokevirtual org.graalvm.polyglot.Value.asString:()Ljava/lang/String;
            areturn
         5: .line 3213
      StackMap locals: org.graalvm.polyglot.Value
      StackMap stack:
            aconst_null
            areturn
        end local 1 // org.graalvm.polyglot.Value arrayElement
        end local 0 // com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1 this
      LocalVariableTable:
        Start  End  Slot          Name  Signature
            0    6     0          this  Lcom/oracle/truffle/polyglot/PolyglotValue$InteropValue$MemberSet$1;
            3    6     1  arrayElement  Lorg/graalvm/polyglot/Value;

  public java.lang.Object next();
    descriptor: ()Ljava/lang/Object;
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=1, locals=1, args_size=1
         0: .line 1
            aload 0
            invokevirtual com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1.next:()Ljava/lang/String;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
}
Signature: Ljava/lang/Object;Ljava/util/Iterator<Ljava/lang/String;>;
SourceFile: "PolyglotValue.java"
EnclosingMethod: com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet.iterator:()Ljava/util/Iterator;
NestHost: com.oracle.truffle.polyglot.PolyglotValue
InnerClasses:
  private final InteropValue = com.oracle.truffle.polyglot.PolyglotValue$InteropValue of com.oracle.truffle.polyglot.PolyglotValue
  private final MemberSet = com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet of com.oracle.truffle.polyglot.PolyglotValue$InteropValue
  com.oracle.truffle.polyglot.PolyglotValue$InteropValue$MemberSet$1