private void removeInternalKeyFromRequest() {
    Set<String> internalKeysNeedToBeRemoved = new HashSet<>();
    for (Map.Entry<String, Object> requestArg : request.getArgs().entrySet()) {
      String requestKey = requestArg.getKey();
      if (requestKey.startsWith(KEY_PREFIX)) {
        internalKeysNeedToBeRemoved.add(requestKey);
      }
    }
    for (String internalKeyNeedToBeRemoved : internalKeysNeedToBeRemoved) {
      request.removeArg(internalKeyNeedToBeRemoved);
    }
  }
Remove the internal key after we send back 100-continue back to customer.
ambry-rest/src/main/java/com/github/ambry/rest/NettyMessageProcessor.java