https://www.graalvm.org/ 
class com.oracle.truffle.object.Debug$GraphvizShapeVisitor implements com.oracle.truffle.object.Debug$DebugShapeVisitor<com.oracle.truffle.object.Debug$GraphvizShapeVisitor>
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.oracle.truffle.object.Debug$GraphvizShapeVisitor
  super_class: java.lang.Object
{
  private final java.util.Set<com.oracle.truffle.api.object.Shape> drawn;
    descriptor: Ljava/util/Set;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Ljava/util/Set<Lcom/oracle/truffle/api/object/Shape;>;

  private final java.lang.StringBuilder sb;
    descriptor: Ljava/lang/StringBuilder;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  static final boolean $assertionsDisabled;
    descriptor: Z
    flags: (0x1018) ACC_STATIC, ACC_FINAL, ACC_SYNTHETIC

  static void <clinit>();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=1, locals=0, args_size=0
         0: .line 248
            ldc Lcom/oracle/truffle/object/Debug;
            invokevirtual java.lang.Class.desiredAssertionStatus:()Z
            ifne 1
            iconst_1
            goto 2
      StackMap locals:
      StackMap stack:
         1: iconst_0
      StackMap locals:
      StackMap stack: int
         2: putstatic com.oracle.truffle.object.Debug$GraphvizShapeVisitor.$assertionsDisabled:Z
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  void <init>();
    descriptor: ()V
    flags: (0x0000) 
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // com.oracle.truffle.object.Debug$GraphvizShapeVisitor this
         0: .line 252
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 250
            aload 0 /* this */
            new java.lang.StringBuilder
            dup
            invokespecial java.lang.StringBuilder.<init>:()V
            putfield com.oracle.truffle.object.Debug$GraphvizShapeVisitor.sb:Ljava/lang/StringBuilder;
         2: .line 253
            aload 0 /* this */
            new java.util.HashSet
            dup
            invokespecial java.util.HashSet.<init>:()V
            putfield com.oracle.truffle.object.Debug$GraphvizShapeVisitor.drawn:Ljava/util/Set;
         3: .line 254
            return
        end local 0 // com.oracle.truffle.object.Debug$GraphvizShapeVisitor this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    4     0  this  Lcom/oracle/truffle/object/Debug$GraphvizShapeVisitor;

  public com.oracle.truffle.object.Debug$GraphvizShapeVisitor visitShape(com.oracle.truffle.object.ShapeImpl, java.util.Map<? extends com.oracle.truffle.object.Transition, ? extends com.oracle.truffle.object.ShapeImpl>);
    descriptor: (Lcom/oracle/truffle/object/ShapeImpl;Ljava/util/Map;)Lcom/oracle/truffle/object/Debug$GraphvizShapeVisitor;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=7, args_size=3
        start local 0 // com.oracle.truffle.object.Debug$GraphvizShapeVisitor this
        start local 1 // com.oracle.truffle.object.ShapeImpl shape
        start local 2 // java.util.Map transitions
         0: .line 258
            aload 0 /* this */
            getfield com.oracle.truffle.object.Debug$GraphvizShapeVisitor.drawn:Ljava/util/Set;
            aload 1 /* shape */
            invokeinterface java.util.Set.add:(Ljava/lang/Object;)Z
            ifne 2
         1: .line 259
            aload 0 /* this */
            areturn
         2: .line 262
      StackMap locals:
      StackMap stack:
            ldc "s"
            astore 3 /* prefix */
        start local 3 // java.lang.String prefix
         3: .line 263
            aload 0 /* this */
            getfield com.oracle.truffle.object.Debug$GraphvizShapeVisitor.sb:Ljava/lang/StringBuilder;
            aload 3 /* prefix */
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            aload 1 /* shape */
            invokestatic com.oracle.truffle.object.Debug.getId:(Lcom/oracle/truffle/api/object/Shape;)Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
         4: .line 264
            aload 0 /* this */
            getfield com.oracle.truffle.object.Debug$GraphvizShapeVisitor.sb:Ljava/lang/StringBuilder;
            ldc " [label=\""
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
         5: .line 265
            aload 1 /* shape */
            invokevirtual com.oracle.truffle.object.ShapeImpl.getLastProperty:()Lcom/oracle/truffle/api/object/Property;
            ifnull 8
         6: .line 266
            aload 0 /* this */
            getfield com.oracle.truffle.object.Debug$GraphvizShapeVisitor.sb:Ljava/lang/StringBuilder;
            aload 1 /* shape */
            invokevirtual com.oracle.truffle.object.ShapeImpl.getLastProperty:()Lcom/oracle/truffle/api/object/Property;
            invokevirtual java.lang.Object.toString:()Ljava/lang/String;
            invokestatic com.oracle.truffle.object.Debug$GraphvizShapeVisitor.escapeString:(Ljava/lang/String;)Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
         7: .line 267
            goto 9
         8: .line 268
      StackMap locals: java.lang.String
      StackMap stack:
            aload 0 /* this */
            getfield com.oracle.truffle.object.Debug$GraphvizShapeVisitor.sb:Ljava/lang/StringBuilder;
            ldc "ROOT"
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
         9: .line 270
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield com.oracle.truffle.object.Debug$GraphvizShapeVisitor.sb:Ljava/lang/StringBuilder;
            ldc "\""
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
        10: .line 271
            aload 0 /* this */
            getfield com.oracle.truffle.object.Debug$GraphvizShapeVisitor.sb:Ljava/lang/StringBuilder;
            ldc ", shape=\"rectangle\""
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
        11: .line 272
            aload 1 /* shape */
            invokevirtual com.oracle.truffle.object.ShapeImpl.isValid:()Z
            ifne 13
        12: .line 273
            aload 0 /* this */
            getfield com.oracle.truffle.object.Debug$GraphvizShapeVisitor.sb:Ljava/lang/StringBuilder;
            ldc ", color=\"red\", style=dotted"
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
        13: .line 275
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield com.oracle.truffle.object.Debug$GraphvizShapeVisitor.sb:Ljava/lang/StringBuilder;
            ldc "];"
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
        14: .line 277
            aload 2 /* transitions */
            invokeinterface java.util.Map.entrySet:()Ljava/util/Set;
            invokeinterface java.util.Set.iterator:()Ljava/util/Iterator;
            astore 5
            goto 22
      StackMap locals: com.oracle.truffle.object.Debug$GraphvizShapeVisitor com.oracle.truffle.object.ShapeImpl java.util.Map java.lang.String top java.util.Iterator
      StackMap stack:
        15: aload 5
            invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
            checkcast java.util.Map$Entry
            astore 4 /* entry */
        start local 4 // java.util.Map$Entry entry
        16: .line 278
            aload 4 /* entry */
            invokeinterface java.util.Map$Entry.getValue:()Ljava/lang/Object;
            checkcast com.oracle.truffle.object.ShapeImpl
            astore 6 /* dst */
        start local 6 // com.oracle.truffle.object.ShapeImpl dst
        17: .line 279
            aload 0 /* this */
            aload 6 /* dst */
            invokevirtual com.oracle.truffle.object.Debug$GraphvizShapeVisitor.visitShape:(Lcom/oracle/truffle/object/ShapeImpl;)Ljava/lang/Object;
            pop
        18: .line 280
            getstatic com.oracle.truffle.object.Debug$GraphvizShapeVisitor.$assertionsDisabled:Z
            ifne 19
            aload 0 /* this */
            getfield com.oracle.truffle.object.Debug$GraphvizShapeVisitor.drawn:Ljava/util/Set;
            aload 6 /* dst */
            invokeinterface java.util.Set.contains:(Ljava/lang/Object;)Z
            ifne 19
            new java.lang.AssertionError
            dup
            invokespecial java.lang.AssertionError.<init>:()V
            athrow
        19: .line 282
      StackMap locals: com.oracle.truffle.object.Debug$GraphvizShapeVisitor com.oracle.truffle.object.ShapeImpl java.util.Map java.lang.String java.util.Map$Entry java.util.Iterator com.oracle.truffle.object.ShapeImpl
      StackMap stack:
            aload 0 /* this */
            getfield com.oracle.truffle.object.Debug$GraphvizShapeVisitor.sb:Ljava/lang/StringBuilder;
            aload 3 /* prefix */
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            aload 1 /* shape */
            invokestatic com.oracle.truffle.object.Debug.getId:(Lcom/oracle/truffle/api/object/Shape;)Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            ldc "->"
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            aload 3 /* prefix */
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            aload 6 /* dst */
            invokestatic com.oracle.truffle.object.Debug.getId:(Lcom/oracle/truffle/api/object/Shape;)Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
        20: .line 283
            aload 0 /* this */
            getfield com.oracle.truffle.object.Debug$GraphvizShapeVisitor.sb:Ljava/lang/StringBuilder;
            ldc " [label=\""
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            aload 4 /* entry */
            invokeinterface java.util.Map$Entry.getKey:()Ljava/lang/Object;
            checkcast com.oracle.truffle.object.Transition
            invokevirtual java.lang.Object.toString:()Ljava/lang/String;
            invokestatic com.oracle.truffle.object.Debug$GraphvizShapeVisitor.escapeString:(Ljava/lang/String;)Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            ldc "\"]"
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
        21: .line 284
            aload 0 /* this */
            getfield com.oracle.truffle.object.Debug$GraphvizShapeVisitor.sb:Ljava/lang/StringBuilder;
            ldc ";"
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            pop
        end local 6 // com.oracle.truffle.object.ShapeImpl dst
        end local 4 // java.util.Map$Entry entry
        22: .line 277
      StackMap locals: com.oracle.truffle.object.Debug$GraphvizShapeVisitor com.oracle.truffle.object.ShapeImpl java.util.Map java.lang.String top java.util.Iterator
      StackMap stack:
            aload 5
            invokeinterface java.util.Iterator.hasNext:()Z
            ifne 15
        23: .line 287
            aload 0 /* this */
            areturn
        end local 3 // java.lang.String prefix
        end local 2 // java.util.Map transitions
        end local 1 // com.oracle.truffle.object.ShapeImpl shape
        end local 0 // com.oracle.truffle.object.Debug$GraphvizShapeVisitor this
      LocalVariableTable:
        Start  End  Slot         Name  Signature
            0   24     0         this  Lcom/oracle/truffle/object/Debug$GraphvizShapeVisitor;
            0   24     1        shape  Lcom/oracle/truffle/object/ShapeImpl;
            0   24     2  transitions  Ljava/util/Map<+Lcom/oracle/truffle/object/Transition;+Lcom/oracle/truffle/object/ShapeImpl;>;
            3   24     3       prefix  Ljava/lang/String;
           16   22     4        entry  Ljava/util/Map$Entry<+Lcom/oracle/truffle/object/Transition;+Lcom/oracle/truffle/object/ShapeImpl;>;
           17   22     6          dst  Lcom/oracle/truffle/object/ShapeImpl;
    Signature: (Lcom/oracle/truffle/object/ShapeImpl;Ljava/util/Map<+Lcom/oracle/truffle/object/Transition;+Lcom/oracle/truffle/object/ShapeImpl;>;)Lcom/oracle/truffle/object/Debug$GraphvizShapeVisitor;
    MethodParameters:
             Name  Flags
      shape        
      transitions  

  private static java.lang.String escapeString(java.lang.String);
    descriptor: (Ljava/lang/String;)Ljava/lang/String;
    flags: (0x000a) ACC_PRIVATE, ACC_STATIC
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // java.lang.String str
         0: .line 291
            aload 0 /* str */
            ldc "\\\\"
            ldc "\\\\"
            invokevirtual java.lang.String.replaceAll:(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;
            ldc "\""
            ldc "\\\\\""
            invokevirtual java.lang.String.replaceAll:(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/String;
            areturn
        end local 0 // java.lang.String str
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0   str  Ljava/lang/String;
    MethodParameters:
      Name  Flags
      str   

  public java.lang.String toString();
    descriptor: ()Ljava/lang/String;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // com.oracle.truffle.object.Debug$GraphvizShapeVisitor this
         0: .line 296
            new java.lang.StringBuilder
            dup
            ldc "digraph{"
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            aload 0 /* this */
            getfield com.oracle.truffle.object.Debug$GraphvizShapeVisitor.sb:Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/CharSequence;)Ljava/lang/StringBuilder;
            ldc "}"
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            areturn
        end local 0 // com.oracle.truffle.object.Debug$GraphvizShapeVisitor this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/object/Debug$GraphvizShapeVisitor;

  public java.lang.Object visitShape(com.oracle.truffle.object.ShapeImpl, java.util.Map);
    descriptor: (Lcom/oracle/truffle/object/ShapeImpl;Ljava/util/Map;)Ljava/lang/Object;
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=3, locals=3, args_size=3
         0: .line 1
            aload 0
            aload 1
            aload 2
            invokevirtual com.oracle.truffle.object.Debug$GraphvizShapeVisitor.visitShape:(Lcom/oracle/truffle/object/ShapeImpl;Ljava/util/Map;)Lcom/oracle/truffle/object/Debug$GraphvizShapeVisitor;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
}
Signature: Ljava/lang/Object;Lcom/oracle/truffle/object/Debug$DebugShapeVisitor<Lcom/oracle/truffle/object/Debug$GraphvizShapeVisitor;>;
SourceFile: "Debug.java"
NestHost: com.oracle.truffle.object.Debug
InnerClasses:
  abstract DebugShapeVisitor = com.oracle.truffle.object.Debug$DebugShapeVisitor of com.oracle.truffle.object.Debug
  GraphvizShapeVisitor = com.oracle.truffle.object.Debug$GraphvizShapeVisitor of com.oracle.truffle.object.Debug
  public abstract Entry = java.util.Map$Entry of java.util.Map