public virtual async Task <TEntity> AddAsync(TEntity entity)
        {
            if (entity == null)
            {
                throw new ArgumentNullException($"{nameof(AddAsync)} entity must not be null");
            }

            try
            {
                await _dbContext.AddAsync(entity);

                await _dbContext.SaveChangesAsync();

                return(entity);
            }
            catch (Exception ex)
            {
                throw new Exception($"{nameof(entity)} could not be saved: {ex.Message}");
            }
        }