https://www.graalvm.org/ 
public final class com.oracle.truffle.api.instrumentation.StandardTags$ReadVariableTag extends com.oracle.truffle.api.instrumentation.Tag
  minor version: 0
  major version: 59
  flags: flags: (0x0031) ACC_PUBLIC, ACC_FINAL, ACC_SUPER
  this_class: com.oracle.truffle.api.instrumentation.StandardTags$ReadVariableTag
  super_class: com.oracle.truffle.api.instrumentation.Tag
{
  public static final java.lang.String NAME;
    descriptor: Ljava/lang/String;
    flags: (0x0019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL
    ConstantValue: "readVariableName"

  private void <init>();
    descriptor: ()V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.oracle.truffle.api.instrumentation.StandardTags$ReadVariableTag this
         0: .line 284
            aload 0 /* this */
            invokespecial com.oracle.truffle.api.instrumentation.Tag.<init>:()V
         1: .line 286
            return
        end local 0 // com.oracle.truffle.api.instrumentation.StandardTags$ReadVariableTag this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lcom/oracle/truffle/api/instrumentation/StandardTags$ReadVariableTag;
}
SourceFile: "StandardTags.java"
NestHost: com.oracle.truffle.api.instrumentation.StandardTags
InnerClasses:
  public final ReadVariableTag = com.oracle.truffle.api.instrumentation.StandardTags$ReadVariableTag of com.oracle.truffle.api.instrumentation.StandardTags
  public abstract Identifier = com.oracle.truffle.api.instrumentation.Tag$Identifier of com.oracle.truffle.api.instrumentation.Tag
    RuntimeVisibleAnnotations: 
      com.oracle.truffle.api.instrumentation.Tag$Identifier(value = "READ_VARIABLE")