https://www.graalvm.org/ 
class com.oracle.svm.hosted.dashboard.ToJson$JsonNumber$1 extends com.oracle.svm.hosted.dashboard.ToJson$JsonNumber
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.oracle.svm.hosted.dashboard.ToJson$JsonNumber$1
  super_class: com.oracle.svm.hosted.dashboard.ToJson$JsonNumber
{
  private final java.lang.Number val$number;
    descriptor: Ljava/lang/Number;
    flags: (0x1012) ACC_PRIVATE, ACC_FINAL, ACC_SYNTHETIC

  void <init>(java.lang.Number);
    descriptor: (Ljava/lang/Number;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.oracle.svm.hosted.dashboard.ToJson$JsonNumber$1 this
         0: .line 238
            aload 0 /* this */
            aload 1
            putfield com.oracle.svm.hosted.dashboard.ToJson$JsonNumber$1.val$number:Ljava/lang/Number;
            aload 0 /* this */
            invokespecial com.oracle.svm.hosted.dashboard.ToJson$JsonNumber.<init>:()V
            return
        end local 0 // com.oracle.svm.hosted.dashboard.ToJson$JsonNumber$1 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/svm/hosted/dashboard/ToJson$JsonNumber$1;
    MethodParameters:
            Name  Flags
      val$number  final

  java.lang.Number getNumber();
    descriptor: ()Ljava/lang/Number;
    flags: (0x0000) 
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.oracle.svm.hosted.dashboard.ToJson$JsonNumber$1 this
         0: .line 241
            aload 0 /* this */
            getfield com.oracle.svm.hosted.dashboard.ToJson$JsonNumber$1.val$number:Ljava/lang/Number;
            areturn
        end local 0 // com.oracle.svm.hosted.dashboard.ToJson$JsonNumber$1 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/svm/hosted/dashboard/ToJson$JsonNumber$1;
}
SourceFile: "ToJson.java"
EnclosingMethod: com.oracle.svm.hosted.dashboard.ToJson$JsonNumber.get:(Ljava/lang/Number;)Lcom/oracle/svm/hosted/dashboard/ToJson$JsonNumber;
NestHost: com.oracle.svm.hosted.dashboard.ToJson
InnerClasses:
  public abstract JsonNumber = com.oracle.svm.hosted.dashboard.ToJson$JsonNumber of com.oracle.svm.hosted.dashboard.ToJson
  com.oracle.svm.hosted.dashboard.ToJson$JsonNumber$1