### Question:
DssTcpHandler extends SimpleChannelInboundHandler<Object> { @Override protected void channelRead0(ChannelHandlerContext ctx, Object msg) { String readMessage = ((ByteBuf)msg).toString(Charset.defaultCharset()); for (byte b : readMessage.getBytes()) { message.writeByte(b); } ctx.writeAndFlush(msg); }  @Override void channelReadComplete(ChannelHandlerContext ctx); @Override void exceptionCaught(ChannelHandlerContext ctx, Throwable cause);  }### Answer:
@Test void channelRead0() throws Exception { mockChannelHandlerContextChannelId(ctx, "abcedf"); final DssTcpHandler handler = new DssTcpHandler(); handler.channelRead0(ctx, SEND_MESSAGE); final ByteBuf message = getDssTcpHandlerFieldWithReflection(handler, "message", ByteBuf.class); assertEquals("Send Message", message.toString(Charset.defaultCharset())); }