https://www.graalvm.org/ 
public abstract class com.oracle.truffle.js.nodes.unary.VoidNode extends com.oracle.truffle.js.nodes.unary.JSUnaryNode
  minor version: 0
  major version: 59
  flags: flags: (0x0421) ACC_PUBLIC, ACC_SUPER, ACC_ABSTRACT
  this_class: com.oracle.truffle.js.nodes.unary.VoidNode
  super_class: com.oracle.truffle.js.nodes.unary.JSUnaryNode
{
  protected void <init>(com.oracle.truffle.js.nodes.JavaScriptNode);
    descriptor: (Lcom/oracle/truffle/js/nodes/JavaScriptNode;)V
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.oracle.truffle.js.nodes.unary.VoidNode this
        start local 1 // com.oracle.truffle.js.nodes.JavaScriptNode operand
         0: .line 59
            aload 0 /* this */
            aload 1 /* operand */
            invokespecial com.oracle.truffle.js.nodes.unary.JSUnaryNode.<init>:(Lcom/oracle/truffle/js/nodes/JavaScriptNode;)V
         1: .line 60
            return
        end local 1 // com.oracle.truffle.js.nodes.JavaScriptNode operand
        end local 0 // com.oracle.truffle.js.nodes.unary.VoidNode this
      LocalVariableTable:
        Start  End  Slot     Name  Signature
            0    2     0     this  Lcom/oracle/truffle/js/nodes/unary/VoidNode;
            0    2     1  operand  Lcom/oracle/truffle/js/nodes/JavaScriptNode;
    MethodParameters:
         Name  Flags
      operand  

  public static com.oracle.truffle.js.nodes.JavaScriptNode create(com.oracle.truffle.js.nodes.JavaScriptNode);
    descriptor: (Lcom/oracle/truffle/js/nodes/JavaScriptNode;)Lcom/oracle/truffle/js/nodes/JavaScriptNode;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=3, locals=1, args_size=1
         0: .line 70
            new java.lang.Error
            dup
            ldc "Unresolved compilation problem: \n\tVoidNodeGen cannot be resolved\n"
            invokespecial java.lang.Error.<init>:(Ljava/lang/String;)V
            athrow
      LocalVariableTable:
        Start  End  Slot  Name  Signature
    MethodParameters:
         Name  Flags
      operand  

  public boolean hasTag(java.lang.Class<? extends com.oracle.truffle.api.instrumentation.Tag>);
    descriptor: (Ljava/lang/Class;)Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.oracle.truffle.js.nodes.unary.VoidNode this
        start local 1 // java.lang.Class tag
         0: .line 75
            aload 1 /* tag */
            ldc Lcom/oracle/truffle/js/nodes/instrumentation/JSTags$UnaryOperationTag;
            if_acmpne 2
         1: .line 76
            iconst_1
            ireturn
         2: .line 78
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            aload 1 /* tag */
            invokespecial com.oracle.truffle.js.nodes.unary.JSUnaryNode.hasTag:(Ljava/lang/Class;)Z
            ireturn
        end local 1 // java.lang.Class tag
        end local 0 // com.oracle.truffle.js.nodes.unary.VoidNode this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lcom/oracle/truffle/js/nodes/unary/VoidNode;
            0    3     1   tag  Ljava/lang/Class<+Lcom/oracle/truffle/api/instrumentation/Tag;>;
    Signature: (Ljava/lang/Class<+Lcom/oracle/truffle/api/instrumentation/Tag;>;)Z
    MethodParameters:
      Name  Flags
      tag   

  public java.lang.Object getNodeObject();
    descriptor: ()Ljava/lang/Object;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // com.oracle.truffle.js.nodes.unary.VoidNode this
         0: .line 84
            ldc "operator"
            aload 0 /* this */
            invokevirtual java.lang.Object.getClass:()Ljava/lang/Class;
            ldc Lcom/oracle/truffle/api/nodes/NodeInfo;
            invokevirtual java.lang.Class.getAnnotation:(Ljava/lang/Class;)Ljava/lang/annotation/Annotation;
            checkcast com.oracle.truffle.api.nodes.NodeInfo
            invokeinterface com.oracle.truffle.api.nodes.NodeInfo.shortName:()Ljava/lang/String;
            invokestatic com.oracle.truffle.js.nodes.instrumentation.JSTags.createNodeObjectDescriptor:(Ljava/lang/String;Ljava/lang/Object;)Lcom/oracle/truffle/js/nodes/instrumentation/NodeObjectDescriptor;
            areturn
        end local 0 // com.oracle.truffle.js.nodes.unary.VoidNode this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/js/nodes/unary/VoidNode;

  public boolean isResultAlwaysOfType(java.lang.Class<?>);
    descriptor: (Ljava/lang/Class;)Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.oracle.truffle.js.nodes.unary.VoidNode this
        start local 1 // java.lang.Class clazz
         0: .line 89
            aload 1 /* clazz */
            ldc Lcom/oracle/truffle/js/runtime/objects/Undefined;
            if_acmpne 1
            iconst_1
            ireturn
      StackMap locals:
      StackMap stack:
         1: iconst_0
            ireturn
        end local 1 // java.lang.Class clazz
        end local 0 // com.oracle.truffle.js.nodes.unary.VoidNode this
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    2     0   this  Lcom/oracle/truffle/js/nodes/unary/VoidNode;
            0    2     1  clazz  Ljava/lang/Class<*>;
    Signature: (Ljava/lang/Class<*>;)Z
    MethodParameters:
       Name  Flags
      clazz  

  protected java.lang.Object doGeneric(java.lang.Object);
    descriptor: (Ljava/lang/Object;)Ljava/lang/Object;
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=1, locals=2, args_size=2
        start local 0 // com.oracle.truffle.js.nodes.unary.VoidNode this
        start local 1 // java.lang.Object operand
         0: .line 94
            getstatic com.oracle.truffle.js.runtime.objects.Undefined.instance:Lcom/oracle/truffle/js/runtime/objects/JSDynamicObject;
            areturn
        end local 1 // java.lang.Object operand
        end local 0 // com.oracle.truffle.js.nodes.unary.VoidNode this
      LocalVariableTable:
        Start  End  Slot     Name  Signature
            0    1     0     this  Lcom/oracle/truffle/js/nodes/unary/VoidNode;
            0    1     1  operand  Ljava/lang/Object;
    RuntimeVisibleAnnotations: 
      com.oracle.truffle.api.dsl.Specialization()
    MethodParameters:
         Name  Flags
      operand  

  protected com.oracle.truffle.js.nodes.JavaScriptNode copyUninitialized(java.util.Set<java.lang.Class<? extends com.oracle.truffle.api.instrumentation.Tag>>);
    descriptor: (Ljava/util/Set;)Lcom/oracle/truffle/js/nodes/JavaScriptNode;
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // com.oracle.truffle.js.nodes.unary.VoidNode this
         0: .line 99
            new java.lang.Error
            dup
            ldc "Unresolved compilation problem: \n\tVoidNodeGen cannot be resolved\n"
            invokespecial java.lang.Error.<init>:(Ljava/lang/String;)V
            athrow
        end local 0 // com.oracle.truffle.js.nodes.unary.VoidNode this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/js/nodes/unary/VoidNode;
    Signature: (Ljava/util/Set<Ljava/lang/Class<+Lcom/oracle/truffle/api/instrumentation/Tag;>;>;)Lcom/oracle/truffle/js/nodes/JavaScriptNode;
    MethodParameters:
                  Name  Flags
      materializedTags  
}
SourceFile: "VoidNode.java"
InnerClasses:
  public final UnaryOperationTag = com.oracle.truffle.js.nodes.instrumentation.JSTags$UnaryOperationTag of com.oracle.truffle.js.nodes.instrumentation.JSTags
    RuntimeVisibleAnnotations: 
      com.oracle.truffle.api.nodes.NodeInfo(shortName = "void", cost = com.oracle.truffle.api.nodes.NodeCost.NONE:Lcom/oracle/truffle/api/nodes/NodeCost;)