https://www.graalvm.org/ 
class org.graalvm.compiler.truffle.jfr.impl.EventFactoryImpl$1 implements jdk.jfr.FlightRecorderListener
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: org.graalvm.compiler.truffle.jfr.impl.EventFactoryImpl$1
  super_class: java.lang.Object
{
  final org.graalvm.compiler.truffle.jfr.impl.EventFactoryImpl this$0;
    descriptor: Lorg/graalvm/compiler/truffle/jfr/impl/EventFactoryImpl;
    flags: (0x1010) ACC_FINAL, ACC_SYNTHETIC

  void <init>(org.graalvm.compiler.truffle.jfr.impl.EventFactoryImpl);
    descriptor: (Lorg/graalvm/compiler/truffle/jfr/impl/EventFactoryImpl;)V
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // org.graalvm.compiler.truffle.jfr.impl.EventFactoryImpl$1 this
         0: .line 57
            aload 0 /* this */
            aload 1
            putfield org.graalvm.compiler.truffle.jfr.impl.EventFactoryImpl$1.this$0:Lorg/graalvm/compiler/truffle/jfr/impl/EventFactoryImpl;
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // org.graalvm.compiler.truffle.jfr.impl.EventFactoryImpl$1 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/graalvm/compiler/truffle/jfr/impl/EventFactoryImpl$1;
    MethodParameters:
        Name  Flags
      this$0  final

  public void recorderInitialized(jdk.jfr.FlightRecorder);
    descriptor: (Ljdk/jfr/FlightRecorder;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=4, args_size=2
        start local 0 // org.graalvm.compiler.truffle.jfr.impl.EventFactoryImpl$1 this
        start local 1 // jdk.jfr.FlightRecorder recorder
         0: .line 60
            aload 0 /* this */
            getfield org.graalvm.compiler.truffle.jfr.impl.EventFactoryImpl$1.this$0:Lorg/graalvm/compiler/truffle/jfr/impl/EventFactoryImpl;
            getfield org.graalvm.compiler.truffle.jfr.impl.EventFactoryImpl.initializationListeners:Ljava/util/List;
            invokeinterface java.util.List.iterator:()Ljava/util/Iterator;
            astore 3
            goto 3
      StackMap locals: org.graalvm.compiler.truffle.jfr.impl.EventFactoryImpl$1 jdk.jfr.FlightRecorder top java.util.Iterator
      StackMap stack:
         1: aload 3
            invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
            checkcast java.lang.Runnable
            astore 2 /* listener */
        start local 2 // java.lang.Runnable listener
         2: .line 61
            aload 2 /* listener */
            invokeinterface java.lang.Runnable.run:()V
        end local 2 // java.lang.Runnable listener
         3: .line 60
      StackMap locals:
      StackMap stack:
            aload 3
            invokeinterface java.util.Iterator.hasNext:()Z
            ifne 1
         4: .line 63
            return
        end local 1 // jdk.jfr.FlightRecorder recorder
        end local 0 // org.graalvm.compiler.truffle.jfr.impl.EventFactoryImpl$1 this
      LocalVariableTable:
        Start  End  Slot      Name  Signature
            0    5     0      this  Lorg/graalvm/compiler/truffle/jfr/impl/EventFactoryImpl$1;
            0    5     1  recorder  Ljdk/jfr/FlightRecorder;
            2    3     2  listener  Ljava/lang/Runnable;
    MethodParameters:
          Name  Flags
      recorder  
}
SourceFile: "EventFactoryImpl.java"
EnclosingMethod: org.graalvm.compiler.truffle.jfr.impl.EventFactoryImpl.<init>:()V
NestHost: org.graalvm.compiler.truffle.jfr.impl.EventFactoryImpl
InnerClasses:
  org.graalvm.compiler.truffle.jfr.impl.EventFactoryImpl$1