https://www.graalvm.org/ 
class com.oracle.truffle.js.runtime.objects.ExportResolution$Null extends com.oracle.truffle.js.runtime.objects.ExportResolution
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.oracle.truffle.js.runtime.objects.ExportResolution$Null
  super_class: com.oracle.truffle.js.runtime.objects.ExportResolution
{
  private void <init>();
    descriptor: ()V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.oracle.truffle.js.runtime.objects.ExportResolution$Null this
         0: .line 147
            aload 0 /* this */
            invokespecial com.oracle.truffle.js.runtime.objects.ExportResolution.<init>:()V
            return
        end local 0 // com.oracle.truffle.js.runtime.objects.ExportResolution$Null this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/js/runtime/objects/ExportResolution$Null;

  public boolean isNull();
    descriptor: ()Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.oracle.truffle.js.runtime.objects.ExportResolution$Null this
         0: .line 150
            iconst_1
            ireturn
        end local 0 // com.oracle.truffle.js.runtime.objects.ExportResolution$Null this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/js/runtime/objects/ExportResolution$Null;
}
SourceFile: "ExportResolution.java"
NestHost: com.oracle.truffle.js.runtime.objects.ExportResolution
InnerClasses:
  private Null = com.oracle.truffle.js.runtime.objects.ExportResolution$Null of com.oracle.truffle.js.runtime.objects.ExportResolution