docs: public void setResponse(Map<String, Object> headers) {
          int size = RES_200.length;
          byte[] len = stringToBytes(String.valueOf(0));
          size += CONTENT_LENGTH.length;
          size += len.length;
          size += TextCommandConstants.RETURN.length;
          if (headers != null) {
              for (Map.Entry<String, Object> entry : headers.entrySet()) {
                  size += stringToBytes(HEADER_CUSTOM_PREFIX + entry.getKey() + ": ").length;
                  size += stringToBytes(entry.getValue().toString()).length;
                  size += TextCommandConstants.RETURN.length;
              }
          }
          size += TextCommandConstants.RETURN.length;
          this.response = ByteBuffer.allocate(size);
          response.put(RES_200);
          response.put(CONTENT_LENGTH);
          response.put(len);
          response.put(TextCommandConstants.RETURN);
          if (headers != null) {
              for (Map.Entry<String, Object> entry : headers.entrySet()) {
                  response.put(stringToBytes(HEADER_CUSTOM_PREFIX + entry.getKey() + ": "));
                  response.put(stringToBytes(entry.getValue().toString()));
                  response.put(TextCommandConstants.RETURN);
              }
          }
          response.put(TextCommandConstants.RETURN);
          response.flip();
      }