ISpecification.cs

public interface ISpecification<T>
{
  Expression<Func<T, bool>> Criteria { get; }
  List<Expression<Func<T, object>>> Includes { get; }
  List<string> IncludeStrings { get; }
  Expression<Func<T, object>> OrderBy { get; }
  Expression<Func<T, object>> OrderByDescending { get; }
  Expression<Func<T, object>> GroupBy { get; }

  int Take { get; }
  int Skip { get; }
  bool IsPagingEnabled { get; }
}