https://www.graalvm.org/ 
class com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl implements java.util.Iterator<com.oracle.truffle.api.TruffleFile$Walker$Event>
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl
  super_class: java.lang.Object
{
  private final int maxDepth;
    descriptor: I
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  private final java.nio.file.LinkOption[] linkOptions;
    descriptor: [Ljava/nio/file/LinkOption;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  private final java.util.Deque<com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl$Dir> stack;
    descriptor: Ljava/util/Deque;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Ljava/util/Deque<Lcom/oracle/truffle/api/TruffleFile$Walker$IteratorImpl$Dir;>;

  private com.oracle.truffle.api.TruffleFile$Walker$Event current;
    descriptor: Lcom/oracle/truffle/api/TruffleFile$Walker$Event;
    flags: (0x0002) ACC_PRIVATE

  void <init>(com.oracle.truffle.api.TruffleFile, int, boolean);
    descriptor: (Lcom/oracle/truffle/api/TruffleFile;IZ)V
    flags: (0x0000) 
    Code:
      stack=5, locals=4, args_size=4
        start local 0 // com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl this
        start local 1 // com.oracle.truffle.api.TruffleFile start
        start local 2 // int maxDepth
        start local 3 // boolean followSymLinks
         0: .line 2390
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 2391
            aload 0 /* this */
            iload 2 /* maxDepth */
            putfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.maxDepth:I
         2: .line 2392
            aload 0 /* this */
            iload 3 /* followSymLinks */
            ifeq 3
            iconst_0
            anewarray java.nio.file.LinkOption
            goto 4
      StackMap locals: com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl com.oracle.truffle.api.TruffleFile int int
      StackMap stack: com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl
         3: iconst_1
            anewarray java.nio.file.LinkOption
            dup
            iconst_0
            getstatic java.nio.file.LinkOption.NOFOLLOW_LINKS:Ljava/nio/file/LinkOption;
            aastore
      StackMap locals: com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl com.oracle.truffle.api.TruffleFile int int
      StackMap stack: com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl java.nio.file.LinkOption[]
         4: putfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.linkOptions:[Ljava/nio/file/LinkOption;
         5: .line 2393
            aload 0 /* this */
            new java.util.ArrayDeque
            dup
            invokespecial java.util.ArrayDeque.<init>:()V
            putfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.stack:Ljava/util/Deque;
         6: .line 2394
            aload 0 /* this */
            aload 0 /* this */
            aload 1 /* start */
            invokevirtual com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.enter:(Lcom/oracle/truffle/api/TruffleFile;)Lcom/oracle/truffle/api/TruffleFile$Walker$Event;
            putfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.current:Lcom/oracle/truffle/api/TruffleFile$Walker$Event;
         7: .line 2395
            return
        end local 3 // boolean followSymLinks
        end local 2 // int maxDepth
        end local 1 // com.oracle.truffle.api.TruffleFile start
        end local 0 // com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl this
      LocalVariableTable:
        Start  End  Slot            Name  Signature
            0    8     0            this  Lcom/oracle/truffle/api/TruffleFile$Walker$IteratorImpl;
            0    8     1           start  Lcom/oracle/truffle/api/TruffleFile;
            0    8     2        maxDepth  I
            0    8     3  followSymLinks  Z
    MethodParameters:
                Name  Flags
      start           
      maxDepth        
      followSymLinks  

  public boolean hasNext();
    descriptor: ()Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=6, locals=5, args_size=1
        start local 0 // com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl this
         0: .line 2399
            aload 0 /* this */
            getfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.current:Lcom/oracle/truffle/api/TruffleFile$Walker$Event;
            ifnonnull 22
         1: .line 2400
            aload 0 /* this */
            getfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.stack:Ljava/util/Deque;
            invokeinterface java.util.Deque.peekLast:()Ljava/lang/Object;
            checkcast com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl$Dir
            astore 1 /* top */
        start local 1 // com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl$Dir top
         2: .line 2401
            aload 1 /* top */
            ifnull 22
         3: .line 2402
            aconst_null
            astore 2 /* ioe */
        start local 2 // java.io.IOException ioe
         4: .line 2403
            aconst_null
            astore 3 /* file */
        start local 3 // com.oracle.truffle.api.TruffleFile file
         5: .line 2404
            aload 1 /* top */
            invokevirtual com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl$Dir.isSkipped:()Z
            ifne 10
         6: .line 2406
            aload 1 /* top */
            invokevirtual com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl$Dir.next:()Lcom/oracle/truffle/api/TruffleFile;
            astore 3 /* file */
         7: .line 2407
            goto 10
      StackMap locals: com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl$Dir java.io.IOException com.oracle.truffle.api.TruffleFile
      StackMap stack: java.nio.file.DirectoryIteratorException
         8: astore 4 /* x */
        start local 4 // java.nio.file.DirectoryIteratorException x
         9: .line 2408
            aload 4 /* x */
            invokevirtual java.nio.file.DirectoryIteratorException.getCause:()Ljava/io/IOException;
            astore 2 /* ioe */
        end local 4 // java.nio.file.DirectoryIteratorException x
        10: .line 2411
      StackMap locals:
      StackMap stack:
            aload 3 /* file */
            ifnonnull 21
        11: .line 2413
            aload 1 /* top */
            invokevirtual com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl$Dir.close:()V
        12: .line 2414
            goto 18
      StackMap locals:
      StackMap stack: java.io.IOException
        13: astore 4 /* e */
        start local 4 // java.io.IOException e
        14: .line 2415
            aload 2 /* ioe */
            ifnonnull 17
        15: .line 2416
            aload 4 /* e */
            astore 2 /* ioe */
        16: .line 2417
            goto 18
        17: .line 2418
      StackMap locals: java.io.IOException
      StackMap stack:
            aload 2 /* ioe */
            aload 4 /* e */
            invokevirtual java.io.IOException.addSuppressed:(Ljava/lang/Throwable;)V
        end local 4 // java.io.IOException e
        18: .line 2421
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.stack:Ljava/util/Deque;
            invokeinterface java.util.Deque.removeLast:()Ljava/lang/Object;
            pop
        19: .line 2422
            aload 0 /* this */
            new com.oracle.truffle.api.TruffleFile$Walker$Event
            dup
            getstatic com.oracle.truffle.api.TruffleFile$Walker$Event$Type.POST_VISIT_DIRECTORY:Lcom/oracle/truffle/api/TruffleFile$Walker$Event$Type;
            aload 1 /* top */
            getfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl$Dir.directory:Lcom/oracle/truffle/api/TruffleFile;
            aload 2 /* ioe */
            invokespecial com.oracle.truffle.api.TruffleFile$Walker$Event.<init>:(Lcom/oracle/truffle/api/TruffleFile$Walker$Event$Type;Lcom/oracle/truffle/api/TruffleFile;Ljava/io/IOException;)V
            putfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.current:Lcom/oracle/truffle/api/TruffleFile$Walker$Event;
        20: .line 2423
            goto 22
        21: .line 2424
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            aload 0 /* this */
            aload 3 /* file */
            invokevirtual com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.enter:(Lcom/oracle/truffle/api/TruffleFile;)Lcom/oracle/truffle/api/TruffleFile$Walker$Event;
            putfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.current:Lcom/oracle/truffle/api/TruffleFile$Walker$Event;
        end local 3 // com.oracle.truffle.api.TruffleFile file
        end local 2 // java.io.IOException ioe
        end local 1 // com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl$Dir top
        22: .line 2428
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.current:Lcom/oracle/truffle/api/TruffleFile$Walker$Event;
            ifnull 23
            iconst_1
            ireturn
      StackMap locals:
      StackMap stack:
        23: iconst_0
            ireturn
        end local 0 // com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0   24     0  this  Lcom/oracle/truffle/api/TruffleFile$Walker$IteratorImpl;
            2   22     1   top  Lcom/oracle/truffle/api/TruffleFile$Walker$IteratorImpl$Dir;
            4   22     2   ioe  Ljava/io/IOException;
            5   22     3  file  Lcom/oracle/truffle/api/TruffleFile;
            9   10     4     x  Ljava/nio/file/DirectoryIteratorException;
           14   18     4     e  Ljava/io/IOException;
      Exception table:
        from    to  target  type
           6     7       8  Class java.nio.file.DirectoryIteratorException
          11    12      13  Class java.io.IOException

  public com.oracle.truffle.api.TruffleFile$Walker$Event next();
    descriptor: ()Lcom/oracle/truffle/api/TruffleFile$Walker$Event;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=1
        start local 0 // com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl this
         0: .line 2433
            aload 0 /* this */
            getfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.current:Lcom/oracle/truffle/api/TruffleFile$Walker$Event;
            ifnonnull 2
         1: .line 2434
            new java.util.NoSuchElementException
            dup
            invokespecial java.util.NoSuchElementException.<init>:()V
            athrow
         2: .line 2436
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.current:Lcom/oracle/truffle/api/TruffleFile$Walker$Event;
            astore 1 /* res */
        start local 1 // com.oracle.truffle.api.TruffleFile$Walker$Event res
         3: .line 2437
            aload 0 /* this */
            aconst_null
            putfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.current:Lcom/oracle/truffle/api/TruffleFile$Walker$Event;
         4: .line 2438
            aload 1 /* res */
            areturn
        end local 1 // com.oracle.truffle.api.TruffleFile$Walker$Event res
        end local 0 // com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    5     0  this  Lcom/oracle/truffle/api/TruffleFile$Walker$IteratorImpl;
            3    5     1   res  Lcom/oracle/truffle/api/TruffleFile$Walker$Event;

  private com.oracle.truffle.api.TruffleFile$Walker$Event enter(com.oracle.truffle.api.TruffleFile);
    descriptor: (Lcom/oracle/truffle/api/TruffleFile;)Lcom/oracle/truffle/api/TruffleFile$Walker$Event;
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=6, locals=6, args_size=2
        start local 0 // com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl this
        start local 1 // com.oracle.truffle.api.TruffleFile file
         0: .line 2444
            new com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl$BasicFileAttributesImpl
            dup
            aload 1 /* file */
            getfield com.oracle.truffle.api.TruffleFile.fileSystemContext:Lcom/oracle/truffle/api/TruffleFile$FileSystemContext;
            getfield com.oracle.truffle.api.TruffleFile$FileSystemContext.fileSystem:Lorg/graalvm/polyglot/io/FileSystem;
            aload 1 /* file */
            getfield com.oracle.truffle.api.TruffleFile.normalizedPath:Ljava/nio/file/Path;
            ldc "*"
            aload 0 /* this */
            getfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.linkOptions:[Ljava/nio/file/LinkOption;
            invokeinterface org.graalvm.polyglot.io.FileSystem.readAttributes:(Ljava/nio/file/Path;Ljava/lang/String;[Ljava/nio/file/LinkOption;)Ljava/util/Map;
            invokespecial com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl$BasicFileAttributesImpl.<init>:(Ljava/util/Map;)V
            astore 2 /* attrs */
        start local 2 // java.nio.file.attribute.BasicFileAttributes attrs
         1: .line 2445
            goto 4
        end local 2 // java.nio.file.attribute.BasicFileAttributes attrs
      StackMap locals:
      StackMap stack: java.io.IOException
         2: astore 3 /* ioe */
        start local 3 // java.io.IOException ioe
         3: .line 2446
            new com.oracle.truffle.api.TruffleFile$Walker$Event
            dup
            getstatic com.oracle.truffle.api.TruffleFile$Walker$Event$Type.VISIT:Lcom/oracle/truffle/api/TruffleFile$Walker$Event$Type;
            aload 1 /* file */
            aload 3 /* ioe */
            invokespecial com.oracle.truffle.api.TruffleFile$Walker$Event.<init>:(Lcom/oracle/truffle/api/TruffleFile$Walker$Event$Type;Lcom/oracle/truffle/api/TruffleFile;Ljava/io/IOException;)V
            areturn
        end local 3 // java.io.IOException ioe
        start local 2 // java.nio.file.attribute.BasicFileAttributes attrs
         4: .line 2448
      StackMap locals: java.nio.file.attribute.BasicFileAttributes
      StackMap stack:
            aload 0 /* this */
            getfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.stack:Ljava/util/Deque;
            invokeinterface java.util.Deque.size:()I
            istore 3 /* currentDepth */
        start local 3 // int currentDepth
         5: .line 2449
            iload 3 /* currentDepth */
            aload 0 /* this */
            getfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.maxDepth:I
            if_icmpge 6
            aload 2 /* attrs */
            invokeinterface java.nio.file.attribute.BasicFileAttributes.isDirectory:()Z
            ifne 7
         6: .line 2450
      StackMap locals: int
      StackMap stack:
            new com.oracle.truffle.api.TruffleFile$Walker$Event
            dup
            getstatic com.oracle.truffle.api.TruffleFile$Walker$Event$Type.VISIT:Lcom/oracle/truffle/api/TruffleFile$Walker$Event$Type;
            aload 1 /* file */
            aload 2 /* attrs */
            invokespecial com.oracle.truffle.api.TruffleFile$Walker$Event.<init>:(Lcom/oracle/truffle/api/TruffleFile$Walker$Event$Type;Lcom/oracle/truffle/api/TruffleFile;Ljava/nio/file/attribute/BasicFileAttributes;)V
            areturn
         7: .line 2452
      StackMap locals:
      StackMap stack:
            aconst_null
            astore 4 /* stream */
        start local 4 // java.nio.file.DirectoryStream stream
         8: .line 2454
            aload 1 /* file */
            invokevirtual com.oracle.truffle.api.TruffleFile.newDirectoryStream:()Ljava/nio/file/DirectoryStream;
            astore 4 /* stream */
         9: .line 2455
            goto 12
      StackMap locals: com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl com.oracle.truffle.api.TruffleFile java.nio.file.attribute.BasicFileAttributes int java.nio.file.DirectoryStream
      StackMap stack: java.io.IOException
        10: astore 5 /* ioe */
        start local 5 // java.io.IOException ioe
        11: .line 2456
            new com.oracle.truffle.api.TruffleFile$Walker$Event
            dup
            getstatic com.oracle.truffle.api.TruffleFile$Walker$Event$Type.VISIT:Lcom/oracle/truffle/api/TruffleFile$Walker$Event$Type;
            aload 1 /* file */
            aload 5 /* ioe */
            invokespecial com.oracle.truffle.api.TruffleFile$Walker$Event.<init>:(Lcom/oracle/truffle/api/TruffleFile$Walker$Event$Type;Lcom/oracle/truffle/api/TruffleFile;Ljava/io/IOException;)V
            areturn
        end local 5 // java.io.IOException ioe
        12: .line 2458
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl.stack:Ljava/util/Deque;
            new com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl$Dir
            dup
            aload 1 /* file */
            aload 4 /* stream */
            invokespecial com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl$Dir.<init>:(Lcom/oracle/truffle/api/TruffleFile;Ljava/nio/file/DirectoryStream;)V
            invokeinterface java.util.Deque.addLast:(Ljava/lang/Object;)V
        13: .line 2459
            new com.oracle.truffle.api.TruffleFile$Walker$Event
            dup
            getstatic com.oracle.truffle.api.TruffleFile$Walker$Event$Type.PRE_VISIT_DIRECTORY:Lcom/oracle/truffle/api/TruffleFile$Walker$Event$Type;
            aload 1 /* file */
            aload 2 /* attrs */
            invokespecial com.oracle.truffle.api.TruffleFile$Walker$Event.<init>:(Lcom/oracle/truffle/api/TruffleFile$Walker$Event$Type;Lcom/oracle/truffle/api/TruffleFile;Ljava/nio/file/attribute/BasicFileAttributes;)V
            areturn
        end local 4 // java.nio.file.DirectoryStream stream
        end local 3 // int currentDepth
        end local 2 // java.nio.file.attribute.BasicFileAttributes attrs
        end local 1 // com.oracle.truffle.api.TruffleFile file
        end local 0 // com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl this
      LocalVariableTable:
        Start  End  Slot          Name  Signature
            0   14     0          this  Lcom/oracle/truffle/api/TruffleFile$Walker$IteratorImpl;
            0   14     1          file  Lcom/oracle/truffle/api/TruffleFile;
            1    2     2         attrs  Ljava/nio/file/attribute/BasicFileAttributes;
            4   14     2         attrs  Ljava/nio/file/attribute/BasicFileAttributes;
            3    4     3           ioe  Ljava/io/IOException;
            5   14     3  currentDepth  I
            8   14     4        stream  Ljava/nio/file/DirectoryStream<Lcom/oracle/truffle/api/TruffleFile;>;
           11   12     5           ioe  Ljava/io/IOException;
      Exception table:
        from    to  target  type
           0     1       2  Class java.io.IOException
           8     9      10  Class java.io.IOException
    MethodParameters:
      Name  Flags
      file  

  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.api.TruffleFile$Walker$IteratorImpl.next:()Lcom/oracle/truffle/api/TruffleFile$Walker$Event;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
}
Signature: Ljava/lang/Object;Ljava/util/Iterator<Lcom/oracle/truffle/api/TruffleFile$Walker$Event;>;
SourceFile: "TruffleFile.java"
NestHost: com.oracle.truffle.api.TruffleFile
InnerClasses:
  final FileSystemContext = com.oracle.truffle.api.TruffleFile$FileSystemContext of com.oracle.truffle.api.TruffleFile
  private final Walker = com.oracle.truffle.api.TruffleFile$Walker of com.oracle.truffle.api.TruffleFile
  Event = com.oracle.truffle.api.TruffleFile$Walker$Event of com.oracle.truffle.api.TruffleFile$Walker
  final Type = com.oracle.truffle.api.TruffleFile$Walker$Event$Type of com.oracle.truffle.api.TruffleFile$Walker$Event
  private IteratorImpl = com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl of com.oracle.truffle.api.TruffleFile$Walker
  private final BasicFileAttributesImpl = com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl$BasicFileAttributesImpl of com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl
  private final Dir = com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl$Dir of com.oracle.truffle.api.TruffleFile$Walker$IteratorImpl