public async Task <ActionResult <Coach> > DeleteSpecificCoach(string coachSurname)
        {
            try
            {
                await _repository.DeleteSpecificCoach(coachSurname);

                _logger.LogInformation
                    ($"{_context.Coaches.Where(c => c.Surname == coachSurname).Select(c => c.Name)} {coachSurname} has been deleted.");
                return(Ok());
            }
            catch (System.Exception ext)
            {
                _logger.LogError
                    (ext, $"{_context.Coaches.Where(c => c.Surname == coachSurname).Select(c => c.Name)} {coachSurname} hasn't been deleted.");
                // TODO return error object with proper error code.
                return(BadRequest());
            }
        }