private async Task <TlUser> GetUser(ITelegramClient client)
        {
            var normalizedNumber = NumberToSendMessage.StartsWith("+")
                                       ? NumberToSendMessage.Substring(1, NumberToSendMessage.Length - 1)
                                       : NumberToSendMessage;

            var result = await client.GetContactsAsync();

            return(result.Users.Lists
                   .OfType <TlUser>()
                   .FirstOrDefault(x => x.Phone == normalizedNumber));
        }
        public async Task FillContacts()
        {
            var cont = await _client.GetContactsAsync();

            IEnumerable <TlUser> users    = cont.Users.Lists.Cast <TlUser>();
            List <Contact>       contacts = new List <Contact>();

            foreach (var item in users)
            {
                var contact = new Contact();
                contact.FillValues(item.FirstName, item.LastName, item.Phone, item.Id);
                contacts.Add(contact);
            }
            Contacts = contacts;
        }