async Task<List<ListOfPersonTest>> updatePerson4(ListOfPersonTest person)
 {
     foreach (ListOfPersonTest person1 in listOfPersons)
     {
         if (person1.Mail.Equals(person.Mail.Trim()))
         {
             person1.Mail = person.Mail;
             person1.Name = person.Name;
             person1.Adress = person.Adress;
             person1.Age = person.Age;
             person1.Hobby = person.Hobby;
         }
     }
     return await Task.Run(() => { return listOfPersons; });
 }
 async Task<List<ListOfPersonTest>> addPerson(ListOfPersonTest person)
 {
     if(!string.IsNullOrEmpty(person.Name) && !string.IsNullOrEmpty(person.Mail))
         listOfPersons.Add(person);
     return await Task.Run(() => { return listOfPersons; });
 }
 //public async Task<HttpResponseMessage> addNewPerson(string name, string adress, string mail, UInt16 age, string hobby)
 public async Task<HttpResponseMessage> updatePerson(ListOfPersonTest person)
 {
     try
     {
         //ListOfPersonTest person = new ListOfPersonTest();
         //person.Name = name;
         //person.Adress = adress;
         //person.Mail = mail;
         //person.Age = age;
         //person.Hobby = hobby;
         listOfPersons = await updatePerson4(person);
     }
     catch (Exception ex)
     {
         return Request.CreateErrorResponse(HttpStatusCode.InternalServerError, ex);
     }
     return Request.CreateResponse(HttpStatusCode.OK, listOfPersons);
 }
        public async Task<HttpResponseMessage> GetPersonsByMail(string mail)
        {
            ListOfPersonTest list = new ListOfPersonTest();
            try
            {
                list = await getPersonsByMail(mail);

            }
            catch (Exception ex)
            {
                return Request.CreateErrorResponse(HttpStatusCode.InternalServerError, ex);
            }
            return Request.CreateResponse(HttpStatusCode.OK, list);
        }