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.handler.codec.mqtt.MqttConnectReturnCode extends java.lang.Enum<io.netty.handler.codec.mqtt.MqttConnectReturnCode>
  minor version: 0
  major version: 59
  flags: flags: (0x4031) ACC_PUBLIC, ACC_FINAL, ACC_SUPER, ACC_ANNOTATION
  this_class: io.netty.handler.codec.mqtt.MqttConnectReturnCode
  super_class: java.lang.Enum
{
  public static final io.netty.handler.codec.mqtt.MqttConnectReturnCode CONNECTION_ACCEPTED;
    descriptor: Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
    flags: (0x4019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL, ACC_ANNOTATION

  public static final io.netty.handler.codec.mqtt.MqttConnectReturnCode CONNECTION_REFUSED_UNACCEPTABLE_PROTOCOL_VERSION;
    descriptor: Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
    flags: (0x4019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL, ACC_ANNOTATION

  public static final io.netty.handler.codec.mqtt.MqttConnectReturnCode CONNECTION_REFUSED_IDENTIFIER_REJECTED;
    descriptor: Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
    flags: (0x4019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL, ACC_ANNOTATION

  public static final io.netty.handler.codec.mqtt.MqttConnectReturnCode CONNECTION_REFUSED_SERVER_UNAVAILABLE;
    descriptor: Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
    flags: (0x4019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL, ACC_ANNOTATION

  public static final io.netty.handler.codec.mqtt.MqttConnectReturnCode CONNECTION_REFUSED_BAD_USER_NAME_OR_PASSWORD;
    descriptor: Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
    flags: (0x4019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL, ACC_ANNOTATION

  public static final io.netty.handler.codec.mqtt.MqttConnectReturnCode CONNECTION_REFUSED_NOT_AUTHORIZED;
    descriptor: Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
    flags: (0x4019) ACC_PUBLIC, ACC_STATIC, ACC_FINAL, ACC_ANNOTATION

  private static final java.util.Map<java.lang.Byte, io.netty.handler.codec.mqtt.MqttConnectReturnCode> VALUE_TO_CODE_MAP;
    descriptor: Ljava/util/Map;
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    Signature: Ljava/util/Map<Ljava/lang/Byte;Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;>;

  private final byte byteValue;
    descriptor: B
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  private static final io.netty.handler.codec.mqtt.MqttConnectReturnCode[] ENUM$VALUES;
    descriptor: [Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
    flags: (0x101a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL, ACC_SYNTHETIC

  static void <clinit>();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=5, locals=5, args_size=0
         0: .line 27
            new io.netty.handler.codec.mqtt.MqttConnectReturnCode
            dup
            ldc "CONNECTION_ACCEPTED"
            iconst_0
            iconst_0
            invokespecial io.netty.handler.codec.mqtt.MqttConnectReturnCode.<init>:(Ljava/lang/String;IB)V
            putstatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.CONNECTION_ACCEPTED:Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
         1: .line 28
            new io.netty.handler.codec.mqtt.MqttConnectReturnCode
            dup
            ldc "CONNECTION_REFUSED_UNACCEPTABLE_PROTOCOL_VERSION"
            iconst_1
            iconst_1
            invokespecial io.netty.handler.codec.mqtt.MqttConnectReturnCode.<init>:(Ljava/lang/String;IB)V
            putstatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.CONNECTION_REFUSED_UNACCEPTABLE_PROTOCOL_VERSION:Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
         2: .line 29
            new io.netty.handler.codec.mqtt.MqttConnectReturnCode
            dup
            ldc "CONNECTION_REFUSED_IDENTIFIER_REJECTED"
            iconst_2
            iconst_2
            invokespecial io.netty.handler.codec.mqtt.MqttConnectReturnCode.<init>:(Ljava/lang/String;IB)V
            putstatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.CONNECTION_REFUSED_IDENTIFIER_REJECTED:Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
         3: .line 30
            new io.netty.handler.codec.mqtt.MqttConnectReturnCode
            dup
            ldc "CONNECTION_REFUSED_SERVER_UNAVAILABLE"
            iconst_3
            iconst_3
            invokespecial io.netty.handler.codec.mqtt.MqttConnectReturnCode.<init>:(Ljava/lang/String;IB)V
            putstatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.CONNECTION_REFUSED_SERVER_UNAVAILABLE:Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
         4: .line 31
            new io.netty.handler.codec.mqtt.MqttConnectReturnCode
            dup
            ldc "CONNECTION_REFUSED_BAD_USER_NAME_OR_PASSWORD"
            iconst_4
            iconst_4
            invokespecial io.netty.handler.codec.mqtt.MqttConnectReturnCode.<init>:(Ljava/lang/String;IB)V
            putstatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.CONNECTION_REFUSED_BAD_USER_NAME_OR_PASSWORD:Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
         5: .line 32
            new io.netty.handler.codec.mqtt.MqttConnectReturnCode
            dup
            ldc "CONNECTION_REFUSED_NOT_AUTHORIZED"
            iconst_5
            iconst_5
            invokespecial io.netty.handler.codec.mqtt.MqttConnectReturnCode.<init>:(Ljava/lang/String;IB)V
            putstatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.CONNECTION_REFUSED_NOT_AUTHORIZED:Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
            bipush 6
            anewarray io.netty.handler.codec.mqtt.MqttConnectReturnCode
            dup
            iconst_0
            getstatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.CONNECTION_ACCEPTED:Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
            aastore
            dup
            iconst_1
            getstatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.CONNECTION_REFUSED_UNACCEPTABLE_PROTOCOL_VERSION:Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
            aastore
            dup
            iconst_2
            getstatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.CONNECTION_REFUSED_IDENTIFIER_REJECTED:Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
            aastore
            dup
            iconst_3
            getstatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.CONNECTION_REFUSED_SERVER_UNAVAILABLE:Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
            aastore
            dup
            iconst_4
            getstatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.CONNECTION_REFUSED_BAD_USER_NAME_OR_PASSWORD:Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
            aastore
            dup
            iconst_5
            getstatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.CONNECTION_REFUSED_NOT_AUTHORIZED:Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
            aastore
            putstatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.ENUM$VALUES:[Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
         6: .line 37
            new java.util.HashMap
            dup
            invokespecial java.util.HashMap.<init>:()V
            astore 0 /* valueMap */
        start local 0 // java.util.Map valueMap
         7: .line 38
            invokestatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.values:()[Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
            dup
            astore 4
            arraylength
            istore 3
            iconst_0
            istore 2
            goto 11
      StackMap locals: java.util.Map top int int io.netty.handler.codec.mqtt.MqttConnectReturnCode[]
      StackMap stack:
         8: aload 4
            iload 2
            aaload
            astore 1 /* code */
        start local 1 // io.netty.handler.codec.mqtt.MqttConnectReturnCode code
         9: .line 39
            aload 0 /* valueMap */
            aload 1 /* code */
            getfield io.netty.handler.codec.mqtt.MqttConnectReturnCode.byteValue:B
            invokestatic java.lang.Byte.valueOf:(B)Ljava/lang/Byte;
            aload 1 /* code */
            invokeinterface java.util.Map.put:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
            pop
        end local 1 // io.netty.handler.codec.mqtt.MqttConnectReturnCode code
        10: .line 38
            iinc 2 1
      StackMap locals:
      StackMap stack:
        11: iload 2
            iload 3
            if_icmplt 8
        12: .line 41
            aload 0 /* valueMap */
            invokestatic java.util.Collections.unmodifiableMap:(Ljava/util/Map;)Ljava/util/Map;
            putstatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.VALUE_TO_CODE_MAP:Ljava/util/Map;
        end local 0 // java.util.Map valueMap
        13: .line 42
            return
      LocalVariableTable:
        Start  End  Slot      Name  Signature
            7   13     0  valueMap  Ljava/util/Map<Ljava/lang/Byte;Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;>;
            9   10     1      code  Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;

  private void <init>(java.lang.String, int, byte);
    descriptor: (Ljava/lang/String;IB)V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=3, locals=4, args_size=4
        start local 0 // io.netty.handler.codec.mqtt.MqttConnectReturnCode this
        start local 3 // byte byteValue
         0: .line 46
            aload 0 /* this */
            aload 1
            iload 2
            invokespecial java.lang.Enum.<init>:(Ljava/lang/String;I)V
         1: .line 47
            aload 0 /* this */
            iload 3 /* byteValue */
            putfield io.netty.handler.codec.mqtt.MqttConnectReturnCode.byteValue:B
         2: .line 48
            return
        end local 3 // byte byteValue
        end local 0 // io.netty.handler.codec.mqtt.MqttConnectReturnCode this
      LocalVariableTable:
        Start  End  Slot       Name  Signature
            0    3     0       this  Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
            0    3     3  byteValue  B
    MethodParameters:
               Name  Flags
      $enum$name     
      $enum$ordinal  
      byteValue      

  public byte byteValue();
    descriptor: ()B
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // io.netty.handler.codec.mqtt.MqttConnectReturnCode this
         0: .line 51
            aload 0 /* this */
            getfield io.netty.handler.codec.mqtt.MqttConnectReturnCode.byteValue:B
            ireturn
        end local 0 // io.netty.handler.codec.mqtt.MqttConnectReturnCode this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;

  public static io.netty.handler.codec.mqtt.MqttConnectReturnCode valueOf(byte);
    descriptor: (B)Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=5, locals=1, args_size=1
        start local 0 // byte b
         0: .line 55
            getstatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.VALUE_TO_CODE_MAP:Ljava/util/Map;
            iload 0 /* b */
            invokestatic java.lang.Byte.valueOf:(B)Ljava/lang/Byte;
            invokeinterface java.util.Map.containsKey:(Ljava/lang/Object;)Z
            ifeq 2
         1: .line 56
            getstatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.VALUE_TO_CODE_MAP:Ljava/util/Map;
            iload 0 /* b */
            invokestatic java.lang.Byte.valueOf:(B)Ljava/lang/Byte;
            invokeinterface java.util.Map.get:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast io.netty.handler.codec.mqtt.MqttConnectReturnCode
            areturn
         2: .line 58
      StackMap locals:
      StackMap stack:
            new java.lang.IllegalArgumentException
            dup
            new java.lang.StringBuilder
            dup
            ldc "unknown connect return code: "
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            iload 0 /* b */
            sipush 255
            iand
            invokevirtual java.lang.StringBuilder.append:(I)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            invokespecial java.lang.IllegalArgumentException.<init>:(Ljava/lang/String;)V
            athrow
        end local 0 // byte b
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0     b  B
    MethodParameters:
      Name  Flags
      b     

  public static io.netty.handler.codec.mqtt.MqttConnectReturnCode[] values();
    descriptor: ()[Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=5, locals=3, args_size=0
         0: .line 1
            getstatic io.netty.handler.codec.mqtt.MqttConnectReturnCode.ENUM$VALUES:[Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
            dup
            astore 0
            iconst_0
            aload 0
            arraylength
            dup
            istore 1
            anewarray io.netty.handler.codec.mqtt.MqttConnectReturnCode
            dup
            astore 2
            iconst_0
            iload 1
            invokestatic java.lang.System.arraycopy:(Ljava/lang/Object;ILjava/lang/Object;II)V
            aload 2
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  public static io.netty.handler.codec.mqtt.MqttConnectReturnCode valueOf(java.lang.String);
    descriptor: (Ljava/lang/String;)Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=2, locals=1, args_size=1
         0: .line 1
            ldc Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;
            aload 0
            invokestatic java.lang.Enum.valueOf:(Ljava/lang/Class;Ljava/lang/String;)Ljava/lang/Enum;
            checkcast io.netty.handler.codec.mqtt.MqttConnectReturnCode
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
    MethodParameters:
      Name  Flags
      name  
}
Signature: Ljava/lang/Enum<Lio/netty/handler/codec/mqtt/MqttConnectReturnCode;>;
SourceFile: "MqttConnectReturnCode.java"