// PUT api/Contacts/5
        public async Task<IHttpActionResult> PutContact(int id, Contact contact)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            if (id != contact.ContactId)
            {
                return BadRequest();
            }

            try
            {
                await _repository.Update(contact);
            }
            catch (DbUpdateConcurrencyException)
            {

                if (!ContactExists(id))
                {
                    return NotFound();
                }
                else
                {
                    throw;
                }
            }

            return StatusCode(HttpStatusCode.NoContent);
        }
        public async Task<IHttpActionResult> PostContact(Contact contact)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            await _repository.Add(contact);


            return CreatedAtRoute("DefaultApi", new { id = contact.ContactId }, contact);
        }
 public async Task Update(Contact contact)
 {
     db.Entry(contact).State = EntityState.Modified;
     await db.SaveChangesAsync();
 }
 public async Task<int> Add(Contact contact)
 {
     db.Contacts.Add(contact);
     return await db.SaveChangesAsync();
 }