anchor.diff:                                      | _  -> this.Set().FirstOrDefault(expr))*)
   
       member this.Single(expr : 'TEntity -> bool) = 
  -        this.DTOBuilder().BuildFull(this.Set().FirstOrDefault(expr))
  -
  +        this.DTOBuilder().BuildFull(match this.Set() |> Seq.tryFind expr with
  +                                    | Some(item) -> item
  +                                    | None -> null)
  +    
       member this.SingleAsync([<ParamArray>] id : obj []) = async { return this.Single(id) } |> Async.StartAsTask
       member this.SingleAsync(expr : 'TEntity -> bool) = async { return this.Single(expr) } |> Async.StartAsTask
   
  
positive.code:         | _ -> this.Set().Where(whereExpr).AsQueryable()*)
  
      member this.All(whereExpr : 'TEntity -> bool) = 
          this.Set().Where(whereExpr).AsQueryable()
      
      (*member private this.All(take : int, skip : int, sort : seq<Sort>, filter : Filter, whereFunc : Func<'TEntity, bool>,  buildFunc : seq<'TEntity> -> seq<'TDTO>) = 
          let queryResult = 
  
negative.code:              | defaultSort -> this.All(whereFunc).OrderBy(defaultSort)).ToDataSourceResult(take, skip, sort, filter)
          DataSourceResult<'TDTO>(Data = buildFunc queryResult.Data, Total = queryResult.Total)*)
  
      member private this.All(take : int, skip : int, sort : seq<Sort>, filter : Filter, whereFunc : 'TEntity -> bool, 
                              buildFunc : seq<'TEntity> -> seq<'TDTO>) = 
          let queryResult = 
              (match query { 
                         for item in (typeof<'TEntity>).GetProperties(BindingFlags.Instance ||| BindingFlags.Public) 
  