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 abstract class io.netty.channel.pool.AbstractChannelPoolMap<K, P extends io.netty.channel.pool.ChannelPool> implements io.netty.channel.pool.ChannelPoolMap<K, P>, java.lang.Iterable<java.util.Map$Entry<K, P>>, java.io.Closeable
  minor version: 0
  major version: 59
  flags: flags: (0x0421) ACC_PUBLIC, ACC_SUPER, ACC_ABSTRACT
  this_class: io.netty.channel.pool.AbstractChannelPoolMap
  super_class: java.lang.Object
{
  private final java.util.concurrent.ConcurrentMap<K, P> map;
    descriptor: Ljava/util/concurrent/ConcurrentMap;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Ljava/util/concurrent/ConcurrentMap<TK;TP;>;

  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // io.netty.channel.pool.AbstractChannelPoolMap this
         0: .line 32
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 34
            aload 0 /* this */
            invokestatic io.netty.util.internal.PlatformDependent.newConcurrentHashMap:()Ljava/util/concurrent/ConcurrentMap;
            putfield io.netty.channel.pool.AbstractChannelPoolMap.map:Ljava/util/concurrent/ConcurrentMap;
         2: .line 32
            return
        end local 0 // io.netty.channel.pool.AbstractChannelPoolMap this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lio/netty/channel/pool/AbstractChannelPoolMap<TK;TP;>;

  public final P get();
    descriptor: (Ljava/lang/Object;)Lio/netty/channel/pool/ChannelPool;
    flags: (0x0011) ACC_PUBLIC, ACC_FINAL
    Code:
      stack=3, locals=4, args_size=2
        start local 0 // io.netty.channel.pool.AbstractChannelPoolMap this
        start local 1 // java.lang.Object key
         0: .line 38
            aload 0 /* this */
            getfield io.netty.channel.pool.AbstractChannelPoolMap.map:Ljava/util/concurrent/ConcurrentMap;
            aload 1 /* key */
            ldc "key"
            invokestatic io.netty.util.internal.ObjectUtil.checkNotNull:(Ljava/lang/Object;Ljava/lang/String;)Ljava/lang/Object;
            invokeinterface java.util.concurrent.ConcurrentMap.get:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast io.netty.channel.pool.ChannelPool
            astore 2 /* pool */
        start local 2 // io.netty.channel.pool.ChannelPool pool
         1: .line 39
            aload 2 /* pool */
            ifnonnull 7
         2: .line 40
            aload 0 /* this */
            aload 1 /* key */
            invokevirtual io.netty.channel.pool.AbstractChannelPoolMap.newPool:(Ljava/lang/Object;)Lio/netty/channel/pool/ChannelPool;
            astore 2 /* pool */
         3: .line 41
            aload 0 /* this */
            getfield io.netty.channel.pool.AbstractChannelPoolMap.map:Ljava/util/concurrent/ConcurrentMap;
            aload 1 /* key */
            aload 2 /* pool */
            invokeinterface java.util.concurrent.ConcurrentMap.putIfAbsent:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
            checkcast io.netty.channel.pool.ChannelPool
            astore 3 /* old */
        start local 3 // io.netty.channel.pool.ChannelPool old
         4: .line 42
            aload 3 /* old */
            ifnull 7
         5: .line 44
            aload 2 /* pool */
            invokeinterface io.netty.channel.pool.ChannelPool.close:()V
         6: .line 45
            aload 3 /* old */
            astore 2 /* pool */
        end local 3 // io.netty.channel.pool.ChannelPool old
         7: .line 48
      StackMap locals: io.netty.channel.pool.ChannelPool
      StackMap stack:
            aload 2 /* pool */
            areturn
        end local 2 // io.netty.channel.pool.ChannelPool pool
        end local 1 // java.lang.Object key
        end local 0 // io.netty.channel.pool.AbstractChannelPoolMap this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    8     0  this  Lio/netty/channel/pool/AbstractChannelPoolMap<TK;TP;>;
            0    8     1   key  TK;
            1    8     2  pool  TP;
            4    7     3   old  TP;
    Signature: (TK;)TP;
    MethodParameters:
      Name  Flags
      key   

  public final boolean remove();
    descriptor: (Ljava/lang/Object;)Z
    flags: (0x0011) ACC_PUBLIC, ACC_FINAL
    Code:
      stack=3, locals=3, args_size=2
        start local 0 // io.netty.channel.pool.AbstractChannelPoolMap this
        start local 1 // java.lang.Object key
         0: .line 57
            aload 0 /* this */
            getfield io.netty.channel.pool.AbstractChannelPoolMap.map:Ljava/util/concurrent/ConcurrentMap;
            aload 1 /* key */
            ldc "key"
            invokestatic io.netty.util.internal.ObjectUtil.checkNotNull:(Ljava/lang/Object;Ljava/lang/String;)Ljava/lang/Object;
            invokeinterface java.util.concurrent.ConcurrentMap.remove:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast io.netty.channel.pool.ChannelPool
            astore 2 /* pool */
        start local 2 // io.netty.channel.pool.ChannelPool pool
         1: .line 58
            aload 2 /* pool */
            ifnull 4
         2: .line 59
            aload 2 /* pool */
            invokeinterface io.netty.channel.pool.ChannelPool.close:()V
         3: .line 60
            iconst_1
            ireturn
         4: .line 62
      StackMap locals: io.netty.channel.pool.ChannelPool
      StackMap stack:
            iconst_0
            ireturn
        end local 2 // io.netty.channel.pool.ChannelPool pool
        end local 1 // java.lang.Object key
        end local 0 // io.netty.channel.pool.AbstractChannelPoolMap this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    5     0  this  Lio/netty/channel/pool/AbstractChannelPoolMap<TK;TP;>;
            0    5     1   key  TK;
            1    5     2  pool  TP;
    Signature: (TK;)Z
    MethodParameters:
      Name  Flags
      key   

  public final java.util.Iterator<java.util.Map$Entry<K, P>> iterator();
    descriptor: ()Ljava/util/Iterator;
    flags: (0x0011) ACC_PUBLIC, ACC_FINAL
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // io.netty.channel.pool.AbstractChannelPoolMap this
         0: .line 67
            new io.netty.util.internal.ReadOnlyIterator
            dup
            aload 0 /* this */
            getfield io.netty.channel.pool.AbstractChannelPoolMap.map:Ljava/util/concurrent/ConcurrentMap;
            invokeinterface java.util.concurrent.ConcurrentMap.entrySet:()Ljava/util/Set;
            invokeinterface java.util.Set.iterator:()Ljava/util/Iterator;
            invokespecial io.netty.util.internal.ReadOnlyIterator.<init>:(Ljava/util/Iterator;)V
            areturn
        end local 0 // io.netty.channel.pool.AbstractChannelPoolMap this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lio/netty/channel/pool/AbstractChannelPoolMap<TK;TP;>;
    Signature: ()Ljava/util/Iterator<Ljava/util/Map$Entry<TK;TP;>;>;

  public final int size();
    descriptor: ()I
    flags: (0x0011) ACC_PUBLIC, ACC_FINAL
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // io.netty.channel.pool.AbstractChannelPoolMap this
         0: .line 74
            aload 0 /* this */
            getfield io.netty.channel.pool.AbstractChannelPoolMap.map:Ljava/util/concurrent/ConcurrentMap;
            invokeinterface java.util.concurrent.ConcurrentMap.size:()I
            ireturn
        end local 0 // io.netty.channel.pool.AbstractChannelPoolMap this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lio/netty/channel/pool/AbstractChannelPoolMap<TK;TP;>;

  public final boolean isEmpty();
    descriptor: ()Z
    flags: (0x0011) ACC_PUBLIC, ACC_FINAL
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // io.netty.channel.pool.AbstractChannelPoolMap this
         0: .line 81
            aload 0 /* this */
            getfield io.netty.channel.pool.AbstractChannelPoolMap.map:Ljava/util/concurrent/ConcurrentMap;
            invokeinterface java.util.concurrent.ConcurrentMap.isEmpty:()Z
            ireturn
        end local 0 // io.netty.channel.pool.AbstractChannelPoolMap this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lio/netty/channel/pool/AbstractChannelPoolMap<TK;TP;>;

  public final boolean contains();
    descriptor: (Ljava/lang/Object;)Z
    flags: (0x0011) ACC_PUBLIC, ACC_FINAL
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // io.netty.channel.pool.AbstractChannelPoolMap this
        start local 1 // java.lang.Object key
         0: .line 86
            aload 0 /* this */
            getfield io.netty.channel.pool.AbstractChannelPoolMap.map:Ljava/util/concurrent/ConcurrentMap;
            aload 1 /* key */
            ldc "key"
            invokestatic io.netty.util.internal.ObjectUtil.checkNotNull:(Ljava/lang/Object;Ljava/lang/String;)Ljava/lang/Object;
            invokeinterface java.util.concurrent.ConcurrentMap.containsKey:(Ljava/lang/Object;)Z
            ireturn
        end local 1 // java.lang.Object key
        end local 0 // io.netty.channel.pool.AbstractChannelPoolMap this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lio/netty/channel/pool/AbstractChannelPoolMap<TK;TP;>;
            0    1     1   key  TK;
    Signature: (TK;)Z
    MethodParameters:
      Name  Flags
      key   

  protected abstract P newPool();
    descriptor: (Ljava/lang/Object;)Lio/netty/channel/pool/ChannelPool;
    flags: (0x0404) ACC_PROTECTED, ACC_ABSTRACT
    Signature: (TK;)TP;
    MethodParameters:
      Name  Flags
      key   

  public final void close();
    descriptor: ()V
    flags: (0x0011) ACC_PUBLIC, ACC_FINAL
    Code:
      stack=2, locals=3, args_size=1
        start local 0 // io.netty.channel.pool.AbstractChannelPoolMap this
         0: .line 96
            aload 0 /* this */
            getfield io.netty.channel.pool.AbstractChannelPoolMap.map:Ljava/util/concurrent/ConcurrentMap;
            invokeinterface java.util.concurrent.ConcurrentMap.keySet:()Ljava/util/Set;
            invokeinterface java.util.Set.iterator:()Ljava/util/Iterator;
            astore 2
            goto 3
      StackMap locals: io.netty.channel.pool.AbstractChannelPoolMap top java.util.Iterator
      StackMap stack:
         1: aload 2
            invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
            checkcast java.lang.Object
            astore 1 /* key */
        start local 1 // java.lang.Object key
         2: .line 97
            aload 0 /* this */
            aload 1 /* key */
            invokevirtual io.netty.channel.pool.AbstractChannelPoolMap.remove:(Ljava/lang/Object;)Z
            pop
        end local 1 // java.lang.Object key
         3: .line 96
      StackMap locals:
      StackMap stack:
            aload 2
            invokeinterface java.util.Iterator.hasNext:()Z
            ifne 1
         4: .line 99
            return
        end local 0 // io.netty.channel.pool.AbstractChannelPoolMap this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    5     0  this  Lio/netty/channel/pool/AbstractChannelPoolMap<TK;TP;>;
            2    3     1   key  TK;
}
Signature: <K:Ljava/lang/Object;P::Lio/netty/channel/pool/ChannelPool;>Ljava/lang/Object;Lio/netty/channel/pool/ChannelPoolMap<TK;TP;>;Ljava/lang/Iterable<Ljava/util/Map$Entry<TK;TP;>;>;Ljava/io/Closeable;
SourceFile: "AbstractChannelPoolMap.java"
InnerClasses:
  public abstract Entry = java.util.Map$Entry of java.util.Map