code: public byte[] getResponseBodyAsByteArray() {
          final ByteBuf bodyByteBuf = httpInputMessage.getBody();
          final byte[] bytes = new byte[bodyByteBuf.readableBytes()];
          bodyByteBuf.readBytes(bytes);
          return bytes;
      }
docs: Return the response body as a byte array.
  
  @since 3.0.5