https://www.graalvm.org/ 
class com.oracle.truffle.api.test.polyglot.MultiThreadedLanguage$LanguageContext
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.oracle.truffle.api.test.polyglot.MultiThreadedLanguage$LanguageContext
  super_class: java.lang.Object
{
  int disposeCalled;
    descriptor: I
    flags: (0x0000) 

  final com.oracle.truffle.api.TruffleLanguage$Env env;
    descriptor: Lcom/oracle/truffle/api/TruffleLanguage$Env;
    flags: (0x0010) ACC_FINAL

  void <init>(com.oracle.truffle.api.TruffleLanguage$Env);
    descriptor: (Lcom/oracle/truffle/api/TruffleLanguage$Env;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.oracle.truffle.api.test.polyglot.MultiThreadedLanguage$LanguageContext this
        start local 1 // com.oracle.truffle.api.TruffleLanguage$Env env
         0: .line 70
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 71
            aload 0 /* this */
            aload 1 /* env */
            putfield com.oracle.truffle.api.test.polyglot.MultiThreadedLanguage$LanguageContext.env:Lcom/oracle/truffle/api/TruffleLanguage$Env;
         2: .line 72
            return
        end local 1 // com.oracle.truffle.api.TruffleLanguage$Env env
        end local 0 // com.oracle.truffle.api.test.polyglot.MultiThreadedLanguage$LanguageContext this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lcom/oracle/truffle/api/test/polyglot/MultiThreadedLanguage$LanguageContext;
            0    3     1   env  Lcom/oracle/truffle/api/TruffleLanguage$Env;
    MethodParameters:
      Name  Flags
      env   
}
SourceFile: "MultiThreadedLanguage.java"
NestHost: com.oracle.truffle.api.test.polyglot.MultiThreadedLanguage
InnerClasses:
  public final Env = com.oracle.truffle.api.TruffleLanguage$Env of com.oracle.truffle.api.TruffleLanguage
  LanguageContext = com.oracle.truffle.api.test.polyglot.MultiThreadedLanguage$LanguageContext of com.oracle.truffle.api.test.polyglot.MultiThreadedLanguage