https://www.graalvm.org/ 
public class org.graalvm.compiler.truffle.test.AllocationReporterPartialEvaluationTest$AllocationReporterLanguage extends com.oracle.truffle.api.TruffleLanguage<com.oracle.truffle.api.instrumentation.AllocationReporter>
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: org.graalvm.compiler.truffle.test.AllocationReporterPartialEvaluationTest$AllocationReporterLanguage
  super_class: com.oracle.truffle.api.TruffleLanguage
{
  static final java.lang.String ID;
    descriptor: Ljava/lang/String;
    flags: (0x0018) ACC_STATIC, ACC_FINAL
    ConstantValue: "truffle-allocation-reporter-pe-test-language"

  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.graalvm.compiler.truffle.test.AllocationReporterPartialEvaluationTest$AllocationReporterLanguage this
         0: .line 185
            aload 0 /* this */
            invokespecial com.oracle.truffle.api.TruffleLanguage.<init>:()V
            return
        end local 0 // org.graalvm.compiler.truffle.test.AllocationReporterPartialEvaluationTest$AllocationReporterLanguage this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/graalvm/compiler/truffle/test/AllocationReporterPartialEvaluationTest$AllocationReporterLanguage;

  protected com.oracle.truffle.api.instrumentation.AllocationReporter createContext(com.oracle.truffle.api.TruffleLanguage$Env);
    descriptor: (Lcom/oracle/truffle/api/TruffleLanguage$Env;)Lcom/oracle/truffle/api/instrumentation/AllocationReporter;
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=4, locals=3, args_size=2
        start local 0 // org.graalvm.compiler.truffle.test.AllocationReporterPartialEvaluationTest$AllocationReporterLanguage this
        start local 1 // com.oracle.truffle.api.TruffleLanguage$Env env
         0: .line 191
            aload 1 /* env */
            ldc Lcom/oracle/truffle/api/instrumentation/AllocationReporter;
            invokevirtual com.oracle.truffle.api.TruffleLanguage$Env.lookup:(Ljava/lang/Class;)Ljava/lang/Object;
            checkcast com.oracle.truffle.api.instrumentation.AllocationReporter
            astore 2 /* reporter */
        start local 2 // com.oracle.truffle.api.instrumentation.AllocationReporter reporter
         1: .line 192
            aload 1 /* env */
            ldc Lcom/oracle/truffle/api/instrumentation/AllocationReporter;
            invokevirtual java.lang.Class.getSimpleName:()Ljava/lang/String;
            aload 1 /* env */
            aload 2 /* reporter */
            invokevirtual com.oracle.truffle.api.TruffleLanguage$Env.asGuestValue:(Ljava/lang/Object;)Ljava/lang/Object;
            invokevirtual com.oracle.truffle.api.TruffleLanguage$Env.exportSymbol:(Ljava/lang/String;Ljava/lang/Object;)V
         2: .line 193
            aload 2 /* reporter */
            areturn
        end local 2 // com.oracle.truffle.api.instrumentation.AllocationReporter reporter
        end local 1 // com.oracle.truffle.api.TruffleLanguage$Env env
        end local 0 // org.graalvm.compiler.truffle.test.AllocationReporterPartialEvaluationTest$AllocationReporterLanguage this
      LocalVariableTable:
        Start  End  Slot      Name  Signature
            0    3     0      this  Lorg/graalvm/compiler/truffle/test/AllocationReporterPartialEvaluationTest$AllocationReporterLanguage;
            0    3     1       env  Lcom/oracle/truffle/api/TruffleLanguage$Env;
            1    3     2  reporter  Lcom/oracle/truffle/api/instrumentation/AllocationReporter;
    MethodParameters:
      Name  Flags
      env   

  protected java.lang.Object createContext(com.oracle.truffle.api.TruffleLanguage$Env);
    descriptor: (Lcom/oracle/truffle/api/TruffleLanguage$Env;)Ljava/lang/Object;
    flags: (0x1044) ACC_PROTECTED, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=2, locals=2, args_size=2
         0: .line 1
            aload 0
            aload 1
            invokevirtual org.graalvm.compiler.truffle.test.AllocationReporterPartialEvaluationTest$AllocationReporterLanguage.createContext:(Lcom/oracle/truffle/api/TruffleLanguage$Env;)Lcom/oracle/truffle/api/instrumentation/AllocationReporter;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
}
Signature: Lcom/oracle/truffle/api/TruffleLanguage<Lcom/oracle/truffle/api/instrumentation/AllocationReporter;>;
SourceFile: "AllocationReporterPartialEvaluationTest.java"
NestHost: org.graalvm.compiler.truffle.test.AllocationReporterPartialEvaluationTest
InnerClasses:
  public final Env = com.oracle.truffle.api.TruffleLanguage$Env of com.oracle.truffle.api.TruffleLanguage
  public abstract Registration = com.oracle.truffle.api.TruffleLanguage$Registration of com.oracle.truffle.api.TruffleLanguage
  public AllocationReporterLanguage = org.graalvm.compiler.truffle.test.AllocationReporterPartialEvaluationTest$AllocationReporterLanguage of org.graalvm.compiler.truffle.test.AllocationReporterPartialEvaluationTest
    RuntimeVisibleAnnotations: 
      com.oracle.truffle.api.TruffleLanguage$Registration(id = "truffle-allocation-reporter-pe-test-language", name = "Allocation Reporter PE Test Language")