public async Task ImportByUserNameAndSendMessage()
{
var store = new FileSessionStore();
var client = new TelegramClient(store, "session");
await client.Connect();
Assert.IsTrue(client.IsUserAuthorized());
var res = await client.ImportByUserName(UserNameToSendMessage);
Assert.IsNotNull(res);
await client.SendMessage(res.Value, "Test message from TelegramClient");
}