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.handler.codec.protobuf.ProtobufDecoder extends io.netty.handler.codec.MessageToMessageDecoder<io.netty.buffer.ByteBuf>
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: io.netty.handler.codec.protobuf.ProtobufDecoder
  super_class: io.netty.handler.codec.MessageToMessageDecoder
{
  private static final boolean HAS_PARSER;
    descriptor: Z
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL

  private final com.google.protobuf.MessageLite prototype;
    descriptor: Lcom/google/protobuf/MessageLite;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  private final com.google.protobuf.ExtensionRegistryLite extensionRegistry;
    descriptor: Lcom/google/protobuf/ExtensionRegistryLite;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  static void <clinit>();
    descriptor: ()V
    flags: (0x0008) ACC_STATIC
    Code:
      stack=3, locals=1, args_size=0
         0: .line 70
            iconst_0
            istore 0 /* hasParser */
        start local 0 // boolean hasParser
         1: .line 73
            ldc Lcom/google/protobuf/MessageLite;
            ldc "getParserForType"
            iconst_0
            anewarray java.lang.Class
            invokevirtual java.lang.Class.getDeclaredMethod:(Ljava/lang/String;[Ljava/lang/Class;)Ljava/lang/reflect/Method;
            pop
         2: .line 74
            iconst_1
            istore 0 /* hasParser */
         3: .line 75
            goto 5
      StackMap locals: int
      StackMap stack: java.lang.Throwable
         4: pop
         5: .line 79
      StackMap locals:
      StackMap stack:
            iload 0 /* hasParser */
            putstatic io.netty.handler.codec.protobuf.ProtobufDecoder.HAS_PARSER:Z
        end local 0 // boolean hasParser
         6: .line 80
            return
      LocalVariableTable:
        Start  End  Slot       Name  Signature
            1    6     0  hasParser  Z
      Exception table:
        from    to  target  type
           1     3       4  Class java.lang.Throwable

  public void <init>(com.google.protobuf.MessageLite);
    descriptor: (Lcom/google/protobuf/MessageLite;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // io.netty.handler.codec.protobuf.ProtobufDecoder this
        start local 1 // com.google.protobuf.MessageLite prototype
         0: .line 89
            aload 0 /* this */
            aload 1 /* prototype */
            aconst_null
            invokespecial io.netty.handler.codec.protobuf.ProtobufDecoder.<init>:(Lcom/google/protobuf/MessageLite;Lcom/google/protobuf/ExtensionRegistry;)V
         1: .line 90
            return
        end local 1 // com.google.protobuf.MessageLite prototype
        end local 0 // io.netty.handler.codec.protobuf.ProtobufDecoder this
      LocalVariableTable:
        Start  End  Slot       Name  Signature
            0    2     0       this  Lio/netty/handler/codec/protobuf/ProtobufDecoder;
            0    2     1  prototype  Lcom/google/protobuf/MessageLite;
    MethodParameters:
           Name  Flags
      prototype  

  public void <init>(com.google.protobuf.MessageLite, com.google.protobuf.ExtensionRegistry);
    descriptor: (Lcom/google/protobuf/MessageLite;Lcom/google/protobuf/ExtensionRegistry;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=3
        start local 0 // io.netty.handler.codec.protobuf.ProtobufDecoder this
        start local 1 // com.google.protobuf.MessageLite prototype
        start local 2 // com.google.protobuf.ExtensionRegistry extensionRegistry
         0: .line 93
            aload 0 /* this */
            aload 1 /* prototype */
            aload 2 /* extensionRegistry */
            invokespecial io.netty.handler.codec.protobuf.ProtobufDecoder.<init>:(Lcom/google/protobuf/MessageLite;Lcom/google/protobuf/ExtensionRegistryLite;)V
         1: .line 94
            return
        end local 2 // com.google.protobuf.ExtensionRegistry extensionRegistry
        end local 1 // com.google.protobuf.MessageLite prototype
        end local 0 // io.netty.handler.codec.protobuf.ProtobufDecoder this
      LocalVariableTable:
        Start  End  Slot               Name  Signature
            0    2     0               this  Lio/netty/handler/codec/protobuf/ProtobufDecoder;
            0    2     1          prototype  Lcom/google/protobuf/MessageLite;
            0    2     2  extensionRegistry  Lcom/google/protobuf/ExtensionRegistry;
    MethodParameters:
                   Name  Flags
      prototype          
      extensionRegistry  

  public void <init>(com.google.protobuf.MessageLite, com.google.protobuf.ExtensionRegistryLite);
    descriptor: (Lcom/google/protobuf/MessageLite;Lcom/google/protobuf/ExtensionRegistryLite;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=3
        start local 0 // io.netty.handler.codec.protobuf.ProtobufDecoder this
        start local 1 // com.google.protobuf.MessageLite prototype
        start local 2 // com.google.protobuf.ExtensionRegistryLite extensionRegistry
         0: .line 96
            aload 0 /* this */
            invokespecial io.netty.handler.codec.MessageToMessageDecoder.<init>:()V
         1: .line 97
            aload 1 /* prototype */
            ifnonnull 3
         2: .line 98
            new java.lang.NullPointerException
            dup
            ldc "prototype"
            invokespecial java.lang.NullPointerException.<init>:(Ljava/lang/String;)V
            athrow
         3: .line 100
      StackMap locals: io.netty.handler.codec.protobuf.ProtobufDecoder com.google.protobuf.MessageLite com.google.protobuf.ExtensionRegistryLite
      StackMap stack:
            aload 0 /* this */
            aload 1 /* prototype */
            invokeinterface com.google.protobuf.MessageLite.getDefaultInstanceForType:()Lcom/google/protobuf/MessageLite;
            putfield io.netty.handler.codec.protobuf.ProtobufDecoder.prototype:Lcom/google/protobuf/MessageLite;
         4: .line 101
            aload 0 /* this */
            aload 2 /* extensionRegistry */
            putfield io.netty.handler.codec.protobuf.ProtobufDecoder.extensionRegistry:Lcom/google/protobuf/ExtensionRegistryLite;
         5: .line 102
            return
        end local 2 // com.google.protobuf.ExtensionRegistryLite extensionRegistry
        end local 1 // com.google.protobuf.MessageLite prototype
        end local 0 // io.netty.handler.codec.protobuf.ProtobufDecoder this
      LocalVariableTable:
        Start  End  Slot               Name  Signature
            0    6     0               this  Lio/netty/handler/codec/protobuf/ProtobufDecoder;
            0    6     1          prototype  Lcom/google/protobuf/MessageLite;
            0    6     2  extensionRegistry  Lcom/google/protobuf/ExtensionRegistryLite;
    MethodParameters:
                   Name  Flags
      prototype          
      extensionRegistry  

  protected void decode(io.netty.channel.ChannelHandlerContext, io.netty.buffer.ByteBuf, java.util.List<java.lang.Object>);
    descriptor: (Lio/netty/channel/ChannelHandlerContext;Lio/netty/buffer/ByteBuf;Ljava/util/List;)V
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=6, locals=7, args_size=4
        start local 0 // io.netty.handler.codec.protobuf.ProtobufDecoder this
        start local 1 // io.netty.channel.ChannelHandlerContext ctx
        start local 2 // io.netty.buffer.ByteBuf msg
        start local 3 // java.util.List out
         0: .line 109
            aload 2 /* msg */
            invokevirtual io.netty.buffer.ByteBuf.readableBytes:()I
            istore 6 /* length */
        start local 6 // int length
         1: .line 110
            aload 2 /* msg */
            invokevirtual io.netty.buffer.ByteBuf.hasArray:()Z
            ifeq 5
         2: .line 111
            aload 2 /* msg */
            invokevirtual io.netty.buffer.ByteBuf.array:()[B
            astore 4 /* array */
        start local 4 // byte[] array
         3: .line 112
            aload 2 /* msg */
            invokevirtual io.netty.buffer.ByteBuf.arrayOffset:()I
            aload 2 /* msg */
            invokevirtual io.netty.buffer.ByteBuf.readerIndex:()I
            iadd
            istore 5 /* offset */
        start local 5 // int offset
         4: .line 113
            goto 8
        end local 5 // int offset
        end local 4 // byte[] array
         5: .line 114
      StackMap locals: io.netty.handler.codec.protobuf.ProtobufDecoder io.netty.channel.ChannelHandlerContext io.netty.buffer.ByteBuf java.util.List top top int
      StackMap stack:
            iload 6 /* length */
            newarray 8
            astore 4 /* array */
        start local 4 // byte[] array
         6: .line 115
            aload 2 /* msg */
            aload 2 /* msg */
            invokevirtual io.netty.buffer.ByteBuf.readerIndex:()I
            aload 4 /* array */
            iconst_0
            iload 6 /* length */
            invokevirtual io.netty.buffer.ByteBuf.getBytes:(I[BII)Lio/netty/buffer/ByteBuf;
            pop
         7: .line 116
            iconst_0
            istore 5 /* offset */
        start local 5 // int offset
         8: .line 119
      StackMap locals: io.netty.handler.codec.protobuf.ProtobufDecoder io.netty.channel.ChannelHandlerContext io.netty.buffer.ByteBuf java.util.List byte[] int int
      StackMap stack:
            aload 0 /* this */
            getfield io.netty.handler.codec.protobuf.ProtobufDecoder.extensionRegistry:Lcom/google/protobuf/ExtensionRegistryLite;
            ifnonnull 14
         9: .line 120
            getstatic io.netty.handler.codec.protobuf.ProtobufDecoder.HAS_PARSER:Z
            ifeq 12
        10: .line 121
            aload 3 /* out */
            aload 0 /* this */
            getfield io.netty.handler.codec.protobuf.ProtobufDecoder.prototype:Lcom/google/protobuf/MessageLite;
            invokeinterface com.google.protobuf.MessageLite.getParserForType:()Lcom/google/protobuf/Parser;
            aload 4 /* array */
            iload 5 /* offset */
            iload 6 /* length */
            invokeinterface com.google.protobuf.Parser.parseFrom:([BII)Ljava/lang/Object;
            invokeinterface java.util.List.add:(Ljava/lang/Object;)Z
            pop
        11: .line 122
            goto 24
        12: .line 123
      StackMap locals:
      StackMap stack:
            aload 3 /* out */
            aload 0 /* this */
            getfield io.netty.handler.codec.protobuf.ProtobufDecoder.prototype:Lcom/google/protobuf/MessageLite;
            invokeinterface com.google.protobuf.MessageLite.newBuilderForType:()Lcom/google/protobuf/MessageLite$Builder;
            aload 4 /* array */
            iload 5 /* offset */
            iload 6 /* length */
            invokeinterface com.google.protobuf.MessageLite$Builder.mergeFrom:([BII)Lcom/google/protobuf/MessageLite$Builder;
            invokeinterface com.google.protobuf.MessageLite$Builder.build:()Lcom/google/protobuf/MessageLite;
            invokeinterface java.util.List.add:(Ljava/lang/Object;)Z
            pop
        13: .line 125
            goto 24
        14: .line 126
      StackMap locals:
      StackMap stack:
            getstatic io.netty.handler.codec.protobuf.ProtobufDecoder.HAS_PARSER:Z
            ifeq 19
        15: .line 127
            aload 3 /* out */
            aload 0 /* this */
            getfield io.netty.handler.codec.protobuf.ProtobufDecoder.prototype:Lcom/google/protobuf/MessageLite;
            invokeinterface com.google.protobuf.MessageLite.getParserForType:()Lcom/google/protobuf/Parser;
        16: .line 128
            aload 4 /* array */
            iload 5 /* offset */
            iload 6 /* length */
            aload 0 /* this */
            getfield io.netty.handler.codec.protobuf.ProtobufDecoder.extensionRegistry:Lcom/google/protobuf/ExtensionRegistryLite;
        17: .line 127
            invokeinterface com.google.protobuf.Parser.parseFrom:([BIILcom/google/protobuf/ExtensionRegistryLite;)Ljava/lang/Object;
            invokeinterface java.util.List.add:(Ljava/lang/Object;)Z
            pop
        18: .line 129
            goto 24
        19: .line 130
      StackMap locals:
      StackMap stack:
            aload 3 /* out */
            aload 0 /* this */
            getfield io.netty.handler.codec.protobuf.ProtobufDecoder.prototype:Lcom/google/protobuf/MessageLite;
            invokeinterface com.google.protobuf.MessageLite.newBuilderForType:()Lcom/google/protobuf/MessageLite$Builder;
        20: .line 131
            aload 4 /* array */
            iload 5 /* offset */
            iload 6 /* length */
            aload 0 /* this */
            getfield io.netty.handler.codec.protobuf.ProtobufDecoder.extensionRegistry:Lcom/google/protobuf/ExtensionRegistryLite;
        21: .line 130
            invokeinterface com.google.protobuf.MessageLite$Builder.mergeFrom:([BIILcom/google/protobuf/ExtensionRegistryLite;)Lcom/google/protobuf/MessageLite$Builder;
        22: .line 131
            invokeinterface com.google.protobuf.MessageLite$Builder.build:()Lcom/google/protobuf/MessageLite;
        23: .line 130
            invokeinterface java.util.List.add:(Ljava/lang/Object;)Z
            pop
        24: .line 134
      StackMap locals:
      StackMap stack:
            return
        end local 6 // int length
        end local 5 // int offset
        end local 4 // byte[] array
        end local 3 // java.util.List out
        end local 2 // io.netty.buffer.ByteBuf msg
        end local 1 // io.netty.channel.ChannelHandlerContext ctx
        end local 0 // io.netty.handler.codec.protobuf.ProtobufDecoder this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0   25     0    this  Lio/netty/handler/codec/protobuf/ProtobufDecoder;
            0   25     1     ctx  Lio/netty/channel/ChannelHandlerContext;
            0   25     2     msg  Lio/netty/buffer/ByteBuf;
            0   25     3     out  Ljava/util/List<Ljava/lang/Object;>;
            3    5     4   array  [B
            6   25     4   array  [B
            4    5     5  offset  I
            8   25     5  offset  I
            1   25     6  length  I
    Exceptions:
      throws java.lang.Exception
    Signature: (Lio/netty/channel/ChannelHandlerContext;Lio/netty/buffer/ByteBuf;Ljava/util/List<Ljava/lang/Object;>;)V
    MethodParameters:
      Name  Flags
      ctx   
      msg   
      out   

  protected void decode(io.netty.channel.ChannelHandlerContext, java.lang.Object, java.util.List);
    descriptor: (Lio/netty/channel/ChannelHandlerContext;Ljava/lang/Object;Ljava/util/List;)V
    flags: (0x1044) ACC_PROTECTED, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=4, locals=4, args_size=4
         0: .line 1
            aload 0
            aload 1
            aload 2
            checkcast io.netty.buffer.ByteBuf
            aload 3
            invokevirtual io.netty.handler.codec.protobuf.ProtobufDecoder.decode:(Lio/netty/channel/ChannelHandlerContext;Lio/netty/buffer/ByteBuf;Ljava/util/List;)V
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature
    Exceptions:
      throws java.lang.Exception
}
Signature: Lio/netty/handler/codec/MessageToMessageDecoder<Lio/netty/buffer/ByteBuf;>;
SourceFile: "ProtobufDecoder.java"
InnerClasses:
  public abstract Builder = com.google.protobuf.MessageLite$Builder of com.google.protobuf.MessageLite
  public abstract Sharable = io.netty.channel.ChannelHandler$Sharable of io.netty.channel.ChannelHandler
    RuntimeVisibleAnnotations: 
      io.netty.channel.ChannelHandler$Sharable()