Implementing etag in Azure Funcion

gistfile1.txt

using syron.ETagHelper;
using System.Net;

public static async Task<HttpResponseMessage> Run(HttpRequestMessage req, TraceWriter log)
{
    log.Info("C# HTTP trigger function processed a request.");

    // parse query parameter
    string name = req.GetQueryNameValuePairs()
        .FirstOrDefault(q => string.Compare(q.Key, "name", true) == 0)
        .Value;

    // Get request body
    dynamic data = await req.Content.ReadAsAsync<object>();

    // Set name to query string or body data
    name = name ?? data?.name;
    var responseString = "Hello " + name;

    var etag = ETagCreator.Create("Hello World");

    // get request header
    
    IEnumerable<string> values;
    if (req.Headers.TryGetValues("If-None-Match", out values) && values.First() == etag)
    {
        return req.CreateResponse(HttpStatusCode.NotModified);
    }

    var response = req.CreateResponse(HttpStatusCode.OK, responseString);
    response.Headers.Add("ETag", etag);
    return response;
}