class BodyChunkedInput implements ChunkedInput<ByteBuf> {

    public static final int DEFAULT_CHUNK_SIZE = 8 * 1024;

    private final Body body;
    private final int chunkSize;
    private final long contentLength;
    private boolean endOfInput;
    private long progress;

    BodyChunkedInput(Body body) {
        this.body = requireNonNull(body, "body");
        contentLength = body.getContentLength();
        if (contentLength <= 0) {
            chunkSize = DEFAULT_CHUNK_SIZE;
        } else {
            chunkSize = (int) Math.min(contentLength, DEFAULT_CHUNK_SIZE);
        }
    }

    @Override
    @Deprecated
    public ByteBuf readChunk(ChannelHandlerContext ctx) throws Exception {
        return readChunk(ctx.alloc());
    }

    @Override
    public ByteBuf readChunk(ByteBufAllocator alloc) throws Exception {<FILL_FUNCTION_BODY>}

    @Override
    public boolean isEndOfInput() {
        return endOfInput;
    }

    @Override
    public void close() throws Exception {
        body.close();
    }

    @Override
    public long length() {
        return contentLength;
    }

    @Override
    public long progress() {
        return progress;
    }
}

        if (endOfInput) {
            return null;
        }

        ByteBuf buffer = alloc.buffer(chunkSize);
        Body.BodyState state = body.transferTo(buffer);
        progress += buffer.writerIndex();
        switch (state) {
            case STOP:
                endOfInput = true;
                return buffer;
            case SUSPEND:
                // this will suspend the stream in ChunkedWriteHandler
                buffer.release();
                return null;
            case CONTINUE:
                return buffer;
            default:
                throw new IllegalStateException("Unknown state: " + state);
        }
    
<no_super_class>