public virtual async Task <IList <TEntity> > GetAsync(MultiResultSpec <TEntity> spec)
        {
            var result = await _dbContext.Set <TEntity>().Where(spec.ToExpression()).ToListAsync();

            return(result);
        }
        public async Task <IList <TEntity> > GetAsync(MultiResultSpec <TEntity> spec)
        {
            var result = await _collection.AsQueryable().Where(spec.ToExpression()).ToListAsync();

            return(result);
        }