https://www.graalvm.org/ 
public class com.oracle.truffle.api.test.polyglot.HostAccessTest$ConverterMapTestObject
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: com.oracle.truffle.api.test.polyglot.HostAccessTest$ConverterMapTestObject
  super_class: java.lang.Object
{
  public java.lang.String f0;
    descriptor: Ljava/lang/String;
    flags: (0x0001) ACC_PUBLIC
    RuntimeVisibleAnnotations: 
      org.graalvm.polyglot.HostAccess$Export()

  public java.lang.String f1;
    descriptor: Ljava/lang/String;
    flags: (0x0001) ACC_PUBLIC
    RuntimeVisibleAnnotations: 
      org.graalvm.polyglot.HostAccess$Export()

  void <init>(java.lang.String, java.lang.String);
    descriptor: (Ljava/lang/String;Ljava/lang/String;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=3, args_size=3
        start local 0 // com.oracle.truffle.api.test.polyglot.HostAccessTest$ConverterMapTestObject this
        start local 1 // java.lang.String f0
        start local 2 // java.lang.String f1
         0: .line 660
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 661
            aload 0 /* this */
            aload 1 /* f0 */
            putfield com.oracle.truffle.api.test.polyglot.HostAccessTest$ConverterMapTestObject.f0:Ljava/lang/String;
         2: .line 662
            aload 0 /* this */
            aload 2 /* f1 */
            putfield com.oracle.truffle.api.test.polyglot.HostAccessTest$ConverterMapTestObject.f1:Ljava/lang/String;
         3: .line 663
            return
        end local 2 // java.lang.String f1
        end local 1 // java.lang.String f0
        end local 0 // com.oracle.truffle.api.test.polyglot.HostAccessTest$ConverterMapTestObject this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    4     0  this  Lcom/oracle/truffle/api/test/polyglot/HostAccessTest$ConverterMapTestObject;
            0    4     1    f0  Ljava/lang/String;
            0    4     2    f1  Ljava/lang/String;
    MethodParameters:
      Name  Flags
      f0    
      f1    
}
SourceFile: "HostAccessTest.java"
NestHost: com.oracle.truffle.api.test.polyglot.HostAccessTest
InnerClasses:
  public ConverterMapTestObject = com.oracle.truffle.api.test.polyglot.HostAccessTest$ConverterMapTestObject of com.oracle.truffle.api.test.polyglot.HostAccessTest
  public abstract Export = org.graalvm.polyglot.HostAccess$Export of org.graalvm.polyglot.HostAccess