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.resolver.CompositeNameResolver<T> extends io.netty.resolver.SimpleNameResolver<T>
  minor version: 0
  major version: 59
  flags: flags: (0x0031) ACC_PUBLIC, ACC_FINAL, ACC_SUPER
  this_class: io.netty.resolver.CompositeNameResolver
  super_class: io.netty.resolver.SimpleNameResolver
{
  private final io.netty.resolver.NameResolver<T>[] resolvers;
    descriptor: [Lio/netty/resolver/NameResolver;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: [Lio/netty/resolver/NameResolver<TT;>;

  public void <init>(io.netty.util.concurrent.EventExecutor, io.netty.resolver.NameResolver<T>[]);
    descriptor: (Lio/netty/util/concurrent/EventExecutor;[Lio/netty/resolver/NameResolver;)V
    flags: (0x0081) ACC_PUBLIC, ACC_VARARGS
    Code:
      stack=5, locals=4, args_size=3
        start local 0 // io.netty.resolver.CompositeNameResolver this
        start local 1 // io.netty.util.concurrent.EventExecutor executor
        start local 2 // io.netty.resolver.NameResolver[] resolvers
         0: .line 45
            aload 0 /* this */
            aload 1 /* executor */
            invokespecial io.netty.resolver.SimpleNameResolver.<init>:(Lio/netty/util/concurrent/EventExecutor;)V
         1: .line 46
            aload 2 /* resolvers */
            ldc "resolvers"
            invokestatic io.netty.util.internal.ObjectUtil.checkNotNull:(Ljava/lang/Object;Ljava/lang/String;)Ljava/lang/Object;
            pop
         2: .line 47
            iconst_0
            istore 3 /* i */
        start local 3 // int i
         3: goto 7
         4: .line 48
      StackMap locals: io.netty.resolver.CompositeNameResolver io.netty.util.concurrent.EventExecutor io.netty.resolver.NameResolver[] int
      StackMap stack:
            aload 2 /* resolvers */
            iload 3 /* i */
            aaload
            ifnonnull 6
         5: .line 49
            new java.lang.NullPointerException
            dup
            new java.lang.StringBuilder
            dup
            ldc "resolvers["
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            iload 3 /* i */
            invokevirtual java.lang.StringBuilder.append:(I)Ljava/lang/StringBuilder;
            bipush 93
            invokevirtual java.lang.StringBuilder.append:(C)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            invokespecial java.lang.NullPointerException.<init>:(Ljava/lang/String;)V
            athrow
         6: .line 47
      StackMap locals:
      StackMap stack:
            iinc 3 /* i */ 1
      StackMap locals:
      StackMap stack:
         7: iload 3 /* i */
            aload 2 /* resolvers */
            arraylength
            if_icmplt 4
        end local 3 // int i
         8: .line 52
            aload 2 /* resolvers */
            arraylength
            iconst_2
            if_icmpge 12
         9: .line 53
            new java.lang.IllegalArgumentException
            dup
            new java.lang.StringBuilder
            dup
            ldc "resolvers: "
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            aload 2 /* resolvers */
            invokestatic java.util.Arrays.asList:([Ljava/lang/Object;)Ljava/util/List;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/Object;)Ljava/lang/StringBuilder;
        10: .line 54
            ldc " (expected: at least 2 resolvers)"
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
        11: .line 53
            invokespecial java.lang.IllegalArgumentException.<init>:(Ljava/lang/String;)V
            athrow
        12: .line 56
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            aload 2 /* resolvers */
            invokevirtual io.netty.resolver.NameResolver[].clone:()Ljava/lang/Object;
            checkcast io.netty.resolver.NameResolver[]
            putfield io.netty.resolver.CompositeNameResolver.resolvers:[Lio/netty/resolver/NameResolver;
        13: .line 57
            return
        end local 2 // io.netty.resolver.NameResolver[] resolvers
        end local 1 // io.netty.util.concurrent.EventExecutor executor
        end local 0 // io.netty.resolver.CompositeNameResolver this
      LocalVariableTable:
        Start  End  Slot       Name  Signature
            0   14     0       this  Lio/netty/resolver/CompositeNameResolver<TT;>;
            0   14     1   executor  Lio/netty/util/concurrent/EventExecutor;
            0   14     2  resolvers  [Lio/netty/resolver/NameResolver;
            3    8     3          i  I
    Signature: (Lio/netty/util/concurrent/EventExecutor;[Lio/netty/resolver/NameResolver<TT;>;)V
    MethodParameters:
           Name  Flags
      executor   
      resolvers  

  protected void doResolve(java.lang.String, io.netty.util.concurrent.Promise<T>);
    descriptor: (Ljava/lang/String;Lio/netty/util/concurrent/Promise;)V
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=5, locals=3, args_size=3
        start local 0 // io.netty.resolver.CompositeNameResolver this
        start local 1 // java.lang.String inetHost
        start local 2 // io.netty.util.concurrent.Promise promise
         0: .line 61
            aload 0 /* this */
            aload 1 /* inetHost */
            aload 2 /* promise */
            iconst_0
            aconst_null
            invokevirtual io.netty.resolver.CompositeNameResolver.doResolveRec:(Ljava/lang/String;Lio/netty/util/concurrent/Promise;ILjava/lang/Throwable;)V
         1: .line 62
            return
        end local 2 // io.netty.util.concurrent.Promise promise
        end local 1 // java.lang.String inetHost
        end local 0 // io.netty.resolver.CompositeNameResolver this
      LocalVariableTable:
        Start  End  Slot      Name  Signature
            0    2     0      this  Lio/netty/resolver/CompositeNameResolver<TT;>;
            0    2     1  inetHost  Ljava/lang/String;
            0    2     2   promise  Lio/netty/util/concurrent/Promise<TT;>;
    Exceptions:
      throws java.lang.Exception
    Signature: (Ljava/lang/String;Lio/netty/util/concurrent/Promise<TT;>;)V
    MethodParameters:
          Name  Flags
      inetHost  
      promise   

  private void doResolveRec(java.lang.String, io.netty.util.concurrent.Promise<T>, int, java.lang.Throwable);
    descriptor: (Ljava/lang/String;Lio/netty/util/concurrent/Promise;ILjava/lang/Throwable;)V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=7, locals=6, args_size=5
        start local 0 // io.netty.resolver.CompositeNameResolver this
        start local 1 // java.lang.String inetHost
        start local 2 // io.netty.util.concurrent.Promise promise
        start local 3 // int resolverIndex
        start local 4 // java.lang.Throwable lastFailure
         0: .line 68
            iload 3 /* resolverIndex */
            aload 0 /* this */
            getfield io.netty.resolver.CompositeNameResolver.resolvers:[Lio/netty/resolver/NameResolver;
            arraylength
            if_icmplt 3
         1: .line 69
            aload 2 /* promise */
            aload 4 /* lastFailure */
            invokeinterface io.netty.util.concurrent.Promise.setFailure:(Ljava/lang/Throwable;)Lio/netty/util/concurrent/Promise;
            pop
         2: .line 70
            goto 5
         3: .line 71
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield io.netty.resolver.CompositeNameResolver.resolvers:[Lio/netty/resolver/NameResolver;
            iload 3 /* resolverIndex */
            aaload
            astore 5 /* resolver */
        start local 5 // io.netty.resolver.NameResolver resolver
         4: .line 72
            aload 5 /* resolver */
            aload 1 /* inetHost */
            invokeinterface io.netty.resolver.NameResolver.resolve:(Ljava/lang/String;)Lio/netty/util/concurrent/Future;
            new io.netty.resolver.CompositeNameResolver$1
            dup
            aload 0 /* this */
            aload 2 /* promise */
            aload 1 /* inetHost */
            iload 3 /* resolverIndex */
            invokespecial io.netty.resolver.CompositeNameResolver$1.<init>:(Lio/netty/resolver/CompositeNameResolver;Lio/netty/util/concurrent/Promise;Ljava/lang/String;I)V
            invokeinterface io.netty.util.concurrent.Future.addListener:(Lio/netty/util/concurrent/GenericFutureListener;)Lio/netty/util/concurrent/Future;
            pop
        end local 5 // io.netty.resolver.NameResolver resolver
         5: .line 83
      StackMap locals:
      StackMap stack:
            return
        end local 4 // java.lang.Throwable lastFailure
        end local 3 // int resolverIndex
        end local 2 // io.netty.util.concurrent.Promise promise
        end local 1 // java.lang.String inetHost
        end local 0 // io.netty.resolver.CompositeNameResolver this
      LocalVariableTable:
        Start  End  Slot           Name  Signature
            0    6     0           this  Lio/netty/resolver/CompositeNameResolver<TT;>;
            0    6     1       inetHost  Ljava/lang/String;
            0    6     2        promise  Lio/netty/util/concurrent/Promise<TT;>;
            0    6     3  resolverIndex  I
            0    6     4    lastFailure  Ljava/lang/Throwable;
            4    5     5       resolver  Lio/netty/resolver/NameResolver<TT;>;
    Exceptions:
      throws java.lang.Exception
    Signature: (Ljava/lang/String;Lio/netty/util/concurrent/Promise<TT;>;ILjava/lang/Throwable;)V
    MethodParameters:
               Name  Flags
      inetHost       final
      promise        final
      resolverIndex  final
      lastFailure    

  protected void doResolveAll(java.lang.String, io.netty.util.concurrent.Promise<java.util.List<T>>);
    descriptor: (Ljava/lang/String;Lio/netty/util/concurrent/Promise;)V
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=5, locals=3, args_size=3
        start local 0 // io.netty.resolver.CompositeNameResolver this
        start local 1 // java.lang.String inetHost
        start local 2 // io.netty.util.concurrent.Promise promise
         0: .line 87
            aload 0 /* this */
            aload 1 /* inetHost */
            aload 2 /* promise */
            iconst_0
            aconst_null
            invokevirtual io.netty.resolver.CompositeNameResolver.doResolveAllRec:(Ljava/lang/String;Lio/netty/util/concurrent/Promise;ILjava/lang/Throwable;)V
         1: .line 88
            return
        end local 2 // io.netty.util.concurrent.Promise promise
        end local 1 // java.lang.String inetHost
        end local 0 // io.netty.resolver.CompositeNameResolver this
      LocalVariableTable:
        Start  End  Slot      Name  Signature
            0    2     0      this  Lio/netty/resolver/CompositeNameResolver<TT;>;
            0    2     1  inetHost  Ljava/lang/String;
            0    2     2   promise  Lio/netty/util/concurrent/Promise<Ljava/util/List<TT;>;>;
    Exceptions:
      throws java.lang.Exception
    Signature: (Ljava/lang/String;Lio/netty/util/concurrent/Promise<Ljava/util/List<TT;>;>;)V
    MethodParameters:
          Name  Flags
      inetHost  
      promise   

  private void doResolveAllRec(java.lang.String, io.netty.util.concurrent.Promise<java.util.List<T>>, int, java.lang.Throwable);
    descriptor: (Ljava/lang/String;Lio/netty/util/concurrent/Promise;ILjava/lang/Throwable;)V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=7, locals=6, args_size=5
        start local 0 // io.netty.resolver.CompositeNameResolver this
        start local 1 // java.lang.String inetHost
        start local 2 // io.netty.util.concurrent.Promise promise
        start local 3 // int resolverIndex
        start local 4 // java.lang.Throwable lastFailure
         0: .line 94
            iload 3 /* resolverIndex */
            aload 0 /* this */
            getfield io.netty.resolver.CompositeNameResolver.resolvers:[Lio/netty/resolver/NameResolver;
            arraylength
            if_icmplt 3
         1: .line 95
            aload 2 /* promise */
            aload 4 /* lastFailure */
            invokeinterface io.netty.util.concurrent.Promise.setFailure:(Ljava/lang/Throwable;)Lio/netty/util/concurrent/Promise;
            pop
         2: .line 96
            goto 5
         3: .line 97
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield io.netty.resolver.CompositeNameResolver.resolvers:[Lio/netty/resolver/NameResolver;
            iload 3 /* resolverIndex */
            aaload
            astore 5 /* resolver */
        start local 5 // io.netty.resolver.NameResolver resolver
         4: .line 98
            aload 5 /* resolver */
            aload 1 /* inetHost */
            invokeinterface io.netty.resolver.NameResolver.resolveAll:(Ljava/lang/String;)Lio/netty/util/concurrent/Future;
            new io.netty.resolver.CompositeNameResolver$2
            dup
            aload 0 /* this */
            aload 2 /* promise */
            aload 1 /* inetHost */
            iload 3 /* resolverIndex */
            invokespecial io.netty.resolver.CompositeNameResolver$2.<init>:(Lio/netty/resolver/CompositeNameResolver;Lio/netty/util/concurrent/Promise;Ljava/lang/String;I)V
            invokeinterface io.netty.util.concurrent.Future.addListener:(Lio/netty/util/concurrent/GenericFutureListener;)Lio/netty/util/concurrent/Future;
            pop
        end local 5 // io.netty.resolver.NameResolver resolver
         5: .line 109
      StackMap locals:
      StackMap stack:
            return
        end local 4 // java.lang.Throwable lastFailure
        end local 3 // int resolverIndex
        end local 2 // io.netty.util.concurrent.Promise promise
        end local 1 // java.lang.String inetHost
        end local 0 // io.netty.resolver.CompositeNameResolver this
      LocalVariableTable:
        Start  End  Slot           Name  Signature
            0    6     0           this  Lio/netty/resolver/CompositeNameResolver<TT;>;
            0    6     1       inetHost  Ljava/lang/String;
            0    6     2        promise  Lio/netty/util/concurrent/Promise<Ljava/util/List<TT;>;>;
            0    6     3  resolverIndex  I
            0    6     4    lastFailure  Ljava/lang/Throwable;
            4    5     5       resolver  Lio/netty/resolver/NameResolver<TT;>;
    Exceptions:
      throws java.lang.Exception
    Signature: (Ljava/lang/String;Lio/netty/util/concurrent/Promise<Ljava/util/List<TT;>;>;ILjava/lang/Throwable;)V
    MethodParameters:
               Name  Flags
      inetHost       final
      promise        final
      resolverIndex  final
      lastFailure    
}
Signature: <T:Ljava/lang/Object;>Lio/netty/resolver/SimpleNameResolver<TT;>;
SourceFile: "CompositeNameResolver.java"
NestMembers:
  io.netty.resolver.CompositeNameResolver$1  io.netty.resolver.CompositeNameResolver$2
InnerClasses:
  io.netty.resolver.CompositeNameResolver$1
  io.netty.resolver.CompositeNameResolver$2