private RestChannelConsumer parseExistingDocPercolate(
      PercolateRequest percolateRequest, RestRequest restRequest, NodeClient client) {
    String index = restRequest.param("index");
    String type = restRequest.param("type");
    percolateRequest.indices(
        Strings.splitStringByCommaToArray(restRequest.param("percolate_index", index)));
    percolateRequest.documentType(restRequest.param("percolate_type", type));

    GetRequest getRequest = new GetRequest(index, type, restRequest.param("id"));
    getRequest.routing(restRequest.param("routing"));
    getRequest.preference(restRequest.param("preference"));
    getRequest.refresh(restRequest.paramAsBoolean("refresh", getRequest.refresh()));
    getRequest.realtime(restRequest.paramAsBoolean("realtime", getRequest.realtime()));
    getRequest.version(RestActions.parseVersion(restRequest));
    getRequest.versionType(
        VersionType.fromString(restRequest.param("version_type"), getRequest.versionType()));

    percolateRequest.getRequest(getRequest);
    percolateRequest.routing(restRequest.param("percolate_routing"));
    percolateRequest.preference(restRequest.param("percolate_preference"));
    percolateRequest.source(restRequest.contentOrSourceParam());

    percolateRequest.indicesOptions(
        IndicesOptions.fromRequest(restRequest, percolateRequest.indicesOptions()));
    return channel -> executePercolate(client, percolateRequest, channel);
  }
  @Override
  public RestChannelConsumer prepareRequest(final RestRequest request, final NodeClient client)
      throws IOException {
    UpdateRequest updateRequest =
        new UpdateRequest(request.param("index"), request.param("type"), request.param("id"));
    updateRequest.routing(request.param("routing"));
    updateRequest.parent(request.param("parent"));
    updateRequest.timeout(request.paramAsTime("timeout", updateRequest.timeout()));
    updateRequest.setRefreshPolicy(request.param("refresh"));
    String waitForActiveShards = request.param("wait_for_active_shards");
    if (waitForActiveShards != null) {
      updateRequest.waitForActiveShards(ActiveShardCount.parseString(waitForActiveShards));
    }
    updateRequest.docAsUpsert(request.paramAsBoolean("doc_as_upsert", updateRequest.docAsUpsert()));
    FetchSourceContext fetchSourceContext = FetchSourceContext.parseFromRestRequest(request);
    String sField = request.param("fields");
    if (sField != null && fetchSourceContext != null) {
      throw new IllegalArgumentException(
          "[fields] and [_source] cannot be used in the same request");
    }
    if (sField != null) {
      DEPRECATION_LOGGER.deprecated("Deprecated field [fields] used, expected [_source] instead");
      String[] sFields = Strings.splitStringByCommaToArray(sField);
      updateRequest.fields(sFields);
    } else if (fetchSourceContext != null) {
      updateRequest.fetchSource(fetchSourceContext);
    }

    updateRequest.retryOnConflict(
        request.paramAsInt("retry_on_conflict", updateRequest.retryOnConflict()));
    updateRequest.version(RestActions.parseVersion(request));
    updateRequest.versionType(
        VersionType.fromString(request.param("version_type"), updateRequest.versionType()));

    // see if we have it in the body
    if (request.hasContent()) {
      updateRequest.fromXContent(request.content());
      IndexRequest upsertRequest = updateRequest.upsertRequest();
      if (upsertRequest != null) {
        upsertRequest.routing(request.param("routing"));
        upsertRequest.parent(
            request.param(
                "parent")); // order is important, set it after routing, so it will set the routing
        upsertRequest.timestamp(request.param("timestamp"));
        if (request.hasParam("ttl")) {
          upsertRequest.ttl(request.param("ttl"));
        }
        upsertRequest.version(RestActions.parseVersion(request));
        upsertRequest.versionType(
            VersionType.fromString(request.param("version_type"), upsertRequest.versionType()));
      }
      IndexRequest doc = updateRequest.doc();
      if (doc != null) {
        doc.routing(request.param("routing"));
        doc.parent(
            request.param(
                "parent")); // order is important, set it after routing, so it will set the routing
        doc.timestamp(request.param("timestamp"));
        if (request.hasParam("ttl")) {
          doc.ttl(request.param("ttl"));
        }
        doc.version(RestActions.parseVersion(request));
        doc.versionType(VersionType.fromString(request.param("version_type"), doc.versionType()));
      }
    }

    return channel ->
        client.update(
            updateRequest,
            new RestStatusToXContentListener<>(
                channel, r -> r.getLocation(updateRequest.routing())));
  }