public void SendGroupMessageAsync_GroupDoesNotExists_ThrowsItemNotFoundException()
{
var chatId = Guid.NewGuid().ToString();
var messageData = new MessageDataModel()
{
Text = "This is a test message!"
};
_unitOfWork.Setup(u => u.Chats.GetByIdAsync(It.IsAny <string>())).ReturnsAsync((Chat)null);
_messagesService.Awaiting(s => s.SendGroupMessageAsync(chatId, messageData))
.Should().Throw <ItemNotFoundException>();
}