anchor.diff:    SysUtils,
     mUtility;
   
  +type
  +  TDatumShell = class
  +  public
  +    Datum : IVDDatum;
  +    Idx : integer;
  +  end;
  +
   
   { TReadOnlyVirtualDatasetProvider }
   
  
positive.code: 
      FCurrentSortConditions : TSortByConditions;
      FCurrentSortFields : TStringList;
  
      function OnCompare(Item1: Pointer;Item2: Pointer):Integer;
    public
  
negative.code: interface
  
  uses
    DB, Classes, contnrs,
    mVirtualDataSet, mVirtualDataSetInterfaces, mSortConditions;
  
  const
    KEY_FIELD_NAME = '_KEY';
  
  type
  
  