http://netty.io/netty-all/: Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers and clients. (The Netty Project) 
public final class io.netty.util.internal.PromiseNotificationUtil
  minor version: 0
  major version: 59
  flags: flags: (0x0031) ACC_PUBLIC, ACC_FINAL, ACC_SUPER
  this_class: io.netty.util.internal.PromiseNotificationUtil
  super_class: java.lang.Object
{
  private void <init>();
    descriptor: ()V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // io.netty.util.internal.PromiseNotificationUtil this
         0: .line 26
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // io.netty.util.internal.PromiseNotificationUtil this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lio/netty/util/internal/PromiseNotificationUtil;

  public static void tryCancel(io.netty.util.concurrent.Promise<?>, io.netty.util.internal.logging.InternalLogger);
    descriptor: (Lio/netty/util/concurrent/Promise;Lio/netty/util/internal/logging/InternalLogger;)V
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=4, locals=3, args_size=2
        start local 0 // io.netty.util.concurrent.Promise p
        start local 1 // io.netty.util.internal.logging.InternalLogger logger
         0: .line 32
            aload 0 /* p */
            iconst_0
            invokeinterface io.netty.util.concurrent.Promise.cancel:(Z)Z
            ifne 9
            aload 1 /* logger */
            ifnull 9
         1: .line 33
            aload 0 /* p */
            invokeinterface io.netty.util.concurrent.Promise.cause:()Ljava/lang/Throwable;
            astore 2 /* err */
        start local 2 // java.lang.Throwable err
         2: .line 34
            aload 2 /* err */
            ifnonnull 5
         3: .line 35
            aload 1 /* logger */
            ldc "Failed to cancel promise because it has succeeded already: {}"
            aload 0 /* p */
            invokeinterface io.netty.util.internal.logging.InternalLogger.warn:(Ljava/lang/String;Ljava/lang/Object;)V
         4: .line 36
            goto 9
         5: .line 37
      StackMap locals: java.lang.Throwable
      StackMap stack:
            aload 1 /* logger */
         6: .line 38
            ldc "Failed to cancel promise because it has failed already: {}, unnotified cause:"
         7: .line 39
            aload 0 /* p */
            aload 2 /* err */
         8: .line 37
            invokeinterface io.netty.util.internal.logging.InternalLogger.warn:(Ljava/lang/String;Ljava/lang/Object;Ljava/lang/Object;)V
        end local 2 // java.lang.Throwable err
         9: .line 42
      StackMap locals:
      StackMap stack:
            return
        end local 1 // io.netty.util.internal.logging.InternalLogger logger
        end local 0 // io.netty.util.concurrent.Promise p
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0   10     0       p  Lio/netty/util/concurrent/Promise<*>;
            0   10     1  logger  Lio/netty/util/internal/logging/InternalLogger;
            2    9     2     err  Ljava/lang/Throwable;
    Signature: (Lio/netty/util/concurrent/Promise<*>;Lio/netty/util/internal/logging/InternalLogger;)V
    MethodParameters:
        Name  Flags
      p       
      logger  

  public static <V> void trySuccess(io.netty.util.concurrent.Promise<? super V>, V, io.netty.util.internal.logging.InternalLogger);
    descriptor: (Lio/netty/util/concurrent/Promise;Ljava/lang/Object;Lio/netty/util/internal/logging/InternalLogger;)V
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=4, locals=4, args_size=3
        start local 0 // io.netty.util.concurrent.Promise p
        start local 1 // java.lang.Object result
        start local 2 // io.netty.util.internal.logging.InternalLogger logger
         0: .line 48
            aload 0 /* p */
            aload 1 /* result */
            invokeinterface io.netty.util.concurrent.Promise.trySuccess:(Ljava/lang/Object;)Z
            ifne 9
            aload 2 /* logger */
            ifnull 9
         1: .line 49
            aload 0 /* p */
            invokeinterface io.netty.util.concurrent.Promise.cause:()Ljava/lang/Throwable;
            astore 3 /* err */
        start local 3 // java.lang.Throwable err
         2: .line 50
            aload 3 /* err */
            ifnonnull 5
         3: .line 51
            aload 2 /* logger */
            ldc "Failed to mark a promise as success because it has succeeded already: {}"
            aload 0 /* p */
            invokeinterface io.netty.util.internal.logging.InternalLogger.warn:(Ljava/lang/String;Ljava/lang/Object;)V
         4: .line 52
            goto 9
         5: .line 53
      StackMap locals: java.lang.Throwable
      StackMap stack:
            aload 2 /* logger */
         6: .line 54
            ldc "Failed to mark a promise as success because it has failed already: {}, unnotified cause:"
         7: .line 55
            aload 0 /* p */
            aload 3 /* err */
         8: .line 53
            invokeinterface io.netty.util.internal.logging.InternalLogger.warn:(Ljava/lang/String;Ljava/lang/Object;Ljava/lang/Object;)V
        end local 3 // java.lang.Throwable err
         9: .line 58
      StackMap locals:
      StackMap stack:
            return
        end local 2 // io.netty.util.internal.logging.InternalLogger logger
        end local 1 // java.lang.Object result
        end local 0 // io.netty.util.concurrent.Promise p
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0   10     0       p  Lio/netty/util/concurrent/Promise<-TV;>;
            0   10     1  result  TV;
            0   10     2  logger  Lio/netty/util/internal/logging/InternalLogger;
            2    9     3     err  Ljava/lang/Throwable;
    Signature: <V:Ljava/lang/Object;>(Lio/netty/util/concurrent/Promise<-TV;>;TV;Lio/netty/util/internal/logging/InternalLogger;)V
    MethodParameters:
        Name  Flags
      p       
      result  
      logger  

  public static void tryFailure(io.netty.util.concurrent.Promise<?>, java.lang.Throwable, io.netty.util.internal.logging.InternalLogger);
    descriptor: (Lio/netty/util/concurrent/Promise;Ljava/lang/Throwable;Lio/netty/util/internal/logging/InternalLogger;)V
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=6, locals=4, args_size=3
        start local 0 // io.netty.util.concurrent.Promise p
        start local 1 // java.lang.Throwable cause
        start local 2 // io.netty.util.internal.logging.InternalLogger logger
         0: .line 64
            aload 0 /* p */
            aload 1 /* cause */
            invokeinterface io.netty.util.concurrent.Promise.tryFailure:(Ljava/lang/Throwable;)Z
            ifne 9
            aload 2 /* logger */
            ifnull 9
         1: .line 65
            aload 0 /* p */
            invokeinterface io.netty.util.concurrent.Promise.cause:()Ljava/lang/Throwable;
            astore 3 /* err */
        start local 3 // java.lang.Throwable err
         2: .line 66
            aload 3 /* err */
            ifnonnull 5
         3: .line 67
            aload 2 /* logger */
            ldc "Failed to mark a promise as failure because it has succeeded already: {}"
            aload 0 /* p */
            aload 1 /* cause */
            invokeinterface io.netty.util.internal.logging.InternalLogger.warn:(Ljava/lang/String;Ljava/lang/Object;Ljava/lang/Object;)V
         4: .line 68
            goto 9
         5: .line 69
      StackMap locals: java.lang.Throwable
      StackMap stack:
            aload 2 /* logger */
         6: .line 70
            ldc "Failed to mark a promise as failure because it has failed already: {}, unnotified cause: {}"
            iconst_3
            anewarray java.lang.Object
            dup
            iconst_0
         7: .line 71
            aload 0 /* p */
            aastore
            dup
            iconst_1
            aload 3 /* err */
            invokestatic io.netty.util.internal.ThrowableUtil.stackTraceToString:(Ljava/lang/Throwable;)Ljava/lang/String;
            aastore
            dup
            iconst_2
            aload 1 /* cause */
            aastore
         8: .line 69
            invokeinterface io.netty.util.internal.logging.InternalLogger.warn:(Ljava/lang/String;[Ljava/lang/Object;)V
        end local 3 // java.lang.Throwable err
         9: .line 74
      StackMap locals:
      StackMap stack:
            return
        end local 2 // io.netty.util.internal.logging.InternalLogger logger
        end local 1 // java.lang.Throwable cause
        end local 0 // io.netty.util.concurrent.Promise p
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0   10     0       p  Lio/netty/util/concurrent/Promise<*>;
            0   10     1   cause  Ljava/lang/Throwable;
            0   10     2  logger  Lio/netty/util/internal/logging/InternalLogger;
            2    9     3     err  Ljava/lang/Throwable;
    Signature: (Lio/netty/util/concurrent/Promise<*>;Ljava/lang/Throwable;Lio/netty/util/internal/logging/InternalLogger;)V
    MethodParameters:
        Name  Flags
      p       
      cause   
      logger  
}
SourceFile: "PromiseNotificationUtil.java"