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 class io.netty.util.concurrent.PromiseAggregator<V, F extends io.netty.util.concurrent.Future<V>> implements io.netty.util.concurrent.GenericFutureListener<F>
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: io.netty.util.concurrent.PromiseAggregator
  super_class: java.lang.Object
{
  private final io.netty.util.concurrent.Promise<?> aggregatePromise;
    descriptor: Lio/netty/util/concurrent/Promise;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Lio/netty/util/concurrent/Promise<*>;

  private final boolean failPending;
    descriptor: Z
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  private java.util.Set<io.netty.util.concurrent.Promise<V>> pendingPromises;
    descriptor: Ljava/util/Set;
    flags: (0x0002) ACC_PRIVATE
    Signature: Ljava/util/Set<Lio/netty/util/concurrent/Promise<TV;>;>;

  public void <init>(io.netty.util.concurrent.Promise<java.lang.Void>, );
    descriptor: (Lio/netty/util/concurrent/Promise;Z)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=3
        start local 0 // io.netty.util.concurrent.PromiseAggregator this
        start local 1 // io.netty.util.concurrent.Promise aggregatePromise
        start local 2 // boolean failPending
         0: .line 45
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 46
            aload 1 /* aggregatePromise */
            ifnonnull 3
         2: .line 47
            new java.lang.NullPointerException
            dup
            ldc "aggregatePromise"
            invokespecial java.lang.NullPointerException.<init>:(Ljava/lang/String;)V
            athrow
         3: .line 49
      StackMap locals: io.netty.util.concurrent.PromiseAggregator io.netty.util.concurrent.Promise int
      StackMap stack:
            aload 0 /* this */
            aload 1 /* aggregatePromise */
            putfield io.netty.util.concurrent.PromiseAggregator.aggregatePromise:Lio/netty/util/concurrent/Promise;
         4: .line 50
            aload 0 /* this */
            iload 2 /* failPending */
            putfield io.netty.util.concurrent.PromiseAggregator.failPending:Z
         5: .line 51
            return
        end local 2 // boolean failPending
        end local 1 // io.netty.util.concurrent.Promise aggregatePromise
        end local 0 // io.netty.util.concurrent.PromiseAggregator this
      LocalVariableTable:
        Start  End  Slot              Name  Signature
            0    6     0              this  Lio/netty/util/concurrent/PromiseAggregator<TV;TF;>;
            0    6     1  aggregatePromise  Lio/netty/util/concurrent/Promise<Ljava/lang/Void;>;
            0    6     2       failPending  Z
    Signature: (Lio/netty/util/concurrent/Promise<Ljava/lang/Void;>;Z)V
    MethodParameters:
                  Name  Flags
      aggregatePromise  
      failPending       

  public void <init>(io.netty.util.concurrent.Promise<java.lang.Void>);
    descriptor: (Lio/netty/util/concurrent/Promise;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // io.netty.util.concurrent.PromiseAggregator this
        start local 1 // io.netty.util.concurrent.Promise aggregatePromise
         0: .line 58
            aload 0 /* this */
            aload 1 /* aggregatePromise */
            iconst_1
            invokespecial io.netty.util.concurrent.PromiseAggregator.<init>:(Lio/netty/util/concurrent/Promise;Z)V
         1: .line 59
            return
        end local 1 // io.netty.util.concurrent.Promise aggregatePromise
        end local 0 // io.netty.util.concurrent.PromiseAggregator this
      LocalVariableTable:
        Start  End  Slot              Name  Signature
            0    2     0              this  Lio/netty/util/concurrent/PromiseAggregator<TV;TF;>;
            0    2     1  aggregatePromise  Lio/netty/util/concurrent/Promise<Ljava/lang/Void;>;
    Signature: (Lio/netty/util/concurrent/Promise<Ljava/lang/Void;>;)V
    MethodParameters:
                  Name  Flags
      aggregatePromise  

  public final io.netty.util.concurrent.PromiseAggregator<V, F> add(io.netty.util.concurrent.Promise<V>[]);
    descriptor: ([Lio/netty/util/concurrent/Promise;)Lio/netty/util/concurrent/PromiseAggregator;
    flags: (0x0091) ACC_PUBLIC, ACC_FINAL, ACC_VARARGS
    Code:
      stack=4, locals=7, args_size=2
        start local 0 // io.netty.util.concurrent.PromiseAggregator this
        start local 1 // io.netty.util.concurrent.Promise[] promises
         0: .line 66
            aload 1 /* promises */
            ifnonnull 2
         1: .line 67
            new java.lang.NullPointerException
            dup
            ldc "promises"
            invokespecial java.lang.NullPointerException.<init>:(Ljava/lang/String;)V
            athrow
         2: .line 69
      StackMap locals:
      StackMap stack:
            aload 1 /* promises */
            arraylength
            ifne 4
         3: .line 70
            aload 0 /* this */
            areturn
         4: .line 72
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            dup
            astore 2
            monitorenter
         5: .line 73
            aload 0 /* this */
            getfield io.netty.util.concurrent.PromiseAggregator.pendingPromises:Ljava/util/Set;
            ifnonnull 11
         6: .line 75
            aload 1 /* promises */
            arraylength
            iconst_1
            if_icmple 9
         7: .line 76
            aload 1 /* promises */
            arraylength
            istore 3 /* size */
        start local 3 // int size
         8: .line 77
            goto 10
        end local 3 // int size
         9: .line 78
      StackMap locals: io.netty.util.concurrent.PromiseAggregator
      StackMap stack:
            iconst_2
            istore 3 /* size */
        start local 3 // int size
        10: .line 80
      StackMap locals: int
      StackMap stack:
            aload 0 /* this */
            new java.util.LinkedHashSet
            dup
            iload 3 /* size */
            invokespecial java.util.LinkedHashSet.<init>:(I)V
            putfield io.netty.util.concurrent.PromiseAggregator.pendingPromises:Ljava/util/Set;
        end local 3 // int size
        11: .line 82
      StackMap locals:
      StackMap stack:
            aload 1 /* promises */
            dup
            astore 6
            arraylength
            istore 5
            iconst_0
            istore 4
            goto 18
      StackMap locals: io.netty.util.concurrent.PromiseAggregator io.netty.util.concurrent.Promise[] io.netty.util.concurrent.PromiseAggregator top int int io.netty.util.concurrent.Promise[]
      StackMap stack:
        12: aload 6
            iload 4
            aaload
            astore 3 /* p */
        start local 3 // io.netty.util.concurrent.Promise p
        13: .line 83
            aload 3 /* p */
            ifnonnull 15
        14: .line 84
            goto 17
        15: .line 86
      StackMap locals: io.netty.util.concurrent.PromiseAggregator io.netty.util.concurrent.Promise[] io.netty.util.concurrent.PromiseAggregator io.netty.util.concurrent.Promise int int io.netty.util.concurrent.Promise[]
      StackMap stack:
            aload 0 /* this */
            getfield io.netty.util.concurrent.PromiseAggregator.pendingPromises:Ljava/util/Set;
            aload 3 /* p */
            invokeinterface java.util.Set.add:(Ljava/lang/Object;)Z
            pop
        16: .line 87
            aload 3 /* p */
            aload 0 /* this */
            invokeinterface io.netty.util.concurrent.Promise.addListener:(Lio/netty/util/concurrent/GenericFutureListener;)Lio/netty/util/concurrent/Promise;
            pop
        end local 3 // io.netty.util.concurrent.Promise p
        17: .line 82
      StackMap locals: io.netty.util.concurrent.PromiseAggregator io.netty.util.concurrent.Promise[] io.netty.util.concurrent.PromiseAggregator top int int io.netty.util.concurrent.Promise[]
      StackMap stack:
            iinc 4 1
      StackMap locals:
      StackMap stack:
        18: iload 4
            iload 5
            if_icmplt 12
        19: .line 72
            aload 2
            monitorexit
        20: goto 23
      StackMap locals: io.netty.util.concurrent.PromiseAggregator io.netty.util.concurrent.Promise[] io.netty.util.concurrent.PromiseAggregator
      StackMap stack: java.lang.Throwable
        21: aload 2
            monitorexit
        22: athrow
        23: .line 90
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            areturn
        end local 1 // io.netty.util.concurrent.Promise[] promises
        end local 0 // io.netty.util.concurrent.PromiseAggregator this
      LocalVariableTable:
        Start  End  Slot      Name  Signature
            0   24     0      this  Lio/netty/util/concurrent/PromiseAggregator<TV;TF;>;
            0   24     1  promises  [Lio/netty/util/concurrent/Promise;
            8    9     3      size  I
           10   11     3      size  I
           13   17     3         p  Lio/netty/util/concurrent/Promise<TV;>;
      Exception table:
        from    to  target  type
           5    20      21  any
          21    22      21  any
    Signature: ([Lio/netty/util/concurrent/Promise<TV;>;)Lio/netty/util/concurrent/PromiseAggregator<TV;TF;>;
    RuntimeVisibleAnnotations: 
      java.lang.SafeVarargs()
    MethodParameters:
          Name  Flags
      promises  

  public synchronized void operationComplete();
    descriptor: (Lio/netty/util/concurrent/Future;)V
    flags: (0x0021) ACC_PUBLIC, ACC_SYNCHRONIZED
    Code:
      stack=2, locals=5, args_size=2
        start local 0 // io.netty.util.concurrent.PromiseAggregator this
        start local 1 // io.netty.util.concurrent.Future future
         0: .line 95
            aload 0 /* this */
            getfield io.netty.util.concurrent.PromiseAggregator.pendingPromises:Ljava/util/Set;
            ifnonnull 3
         1: .line 96
            aload 0 /* this */
            getfield io.netty.util.concurrent.PromiseAggregator.aggregatePromise:Lio/netty/util/concurrent/Promise;
            aconst_null
            invokeinterface io.netty.util.concurrent.Promise.setSuccess:(Ljava/lang/Object;)Lio/netty/util/concurrent/Promise;
            pop
         2: .line 97
            goto 15
         3: .line 98
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield io.netty.util.concurrent.PromiseAggregator.pendingPromises:Ljava/util/Set;
            aload 1 /* future */
            invokeinterface java.util.Set.remove:(Ljava/lang/Object;)Z
            pop
         4: .line 99
            aload 1 /* future */
            invokeinterface io.netty.util.concurrent.Future.isSuccess:()Z
            ifne 13
         5: .line 100
            aload 1 /* future */
            invokeinterface io.netty.util.concurrent.Future.cause:()Ljava/lang/Throwable;
            astore 2 /* cause */
        start local 2 // java.lang.Throwable cause
         6: .line 101
            aload 0 /* this */
            getfield io.netty.util.concurrent.PromiseAggregator.aggregatePromise:Lio/netty/util/concurrent/Promise;
            aload 2 /* cause */
            invokeinterface io.netty.util.concurrent.Promise.setFailure:(Ljava/lang/Throwable;)Lio/netty/util/concurrent/Promise;
            pop
         7: .line 102
            aload 0 /* this */
            getfield io.netty.util.concurrent.PromiseAggregator.failPending:Z
            ifeq 15
         8: .line 103
            aload 0 /* this */
            getfield io.netty.util.concurrent.PromiseAggregator.pendingPromises:Ljava/util/Set;
            invokeinterface java.util.Set.iterator:()Ljava/util/Iterator;
            astore 4
            goto 11
      StackMap locals: io.netty.util.concurrent.PromiseAggregator io.netty.util.concurrent.Future java.lang.Throwable top java.util.Iterator
      StackMap stack:
         9: aload 4
            invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
            checkcast io.netty.util.concurrent.Promise
            astore 3 /* pendingFuture */
        start local 3 // io.netty.util.concurrent.Promise pendingFuture
        10: .line 104
            aload 3 /* pendingFuture */
            aload 2 /* cause */
            invokeinterface io.netty.util.concurrent.Promise.setFailure:(Ljava/lang/Throwable;)Lio/netty/util/concurrent/Promise;
            pop
        end local 3 // io.netty.util.concurrent.Promise pendingFuture
        11: .line 103
      StackMap locals:
      StackMap stack:
            aload 4
            invokeinterface java.util.Iterator.hasNext:()Z
            ifne 9
        end local 2 // java.lang.Throwable cause
        12: .line 107
            goto 15
        13: .line 108
      StackMap locals: io.netty.util.concurrent.PromiseAggregator io.netty.util.concurrent.Future
      StackMap stack:
            aload 0 /* this */
            getfield io.netty.util.concurrent.PromiseAggregator.pendingPromises:Ljava/util/Set;
            invokeinterface java.util.Set.isEmpty:()Z
            ifeq 15
        14: .line 109
            aload 0 /* this */
            getfield io.netty.util.concurrent.PromiseAggregator.aggregatePromise:Lio/netty/util/concurrent/Promise;
            aconst_null
            invokeinterface io.netty.util.concurrent.Promise.setSuccess:(Ljava/lang/Object;)Lio/netty/util/concurrent/Promise;
            pop
        15: .line 113
      StackMap locals:
      StackMap stack:
            return
        end local 1 // io.netty.util.concurrent.Future future
        end local 0 // io.netty.util.concurrent.PromiseAggregator this
      LocalVariableTable:
        Start  End  Slot           Name  Signature
            0   16     0           this  Lio/netty/util/concurrent/PromiseAggregator<TV;TF;>;
            0   16     1         future  TF;
            6   12     2          cause  Ljava/lang/Throwable;
           10   11     3  pendingFuture  Lio/netty/util/concurrent/Promise<TV;>;
    Exceptions:
      throws java.lang.Exception
    Signature: (TF;)V
    MethodParameters:
        Name  Flags
      future  
}
Signature: <V:Ljava/lang/Object;F::Lio/netty/util/concurrent/Future<TV;>;>Ljava/lang/Object;Lio/netty/util/concurrent/GenericFutureListener<TF;>;
SourceFile: "PromiseAggregator.java"
    RuntimeVisibleAnnotations: 
      java.lang.Deprecated()