anchor.diff:      procedure Trim();
       procedure ChangeToBlankIfNull;
   
  -    class function StringToVariant(const aValue: String): Variant;
  +    class function StringToVariant(const aValue: String; const aAllowBlankValues : boolean): Variant;
       class function VariantToString(const aValue: Variant): String;
   
       function AsString : String; override;
  
positive.code:       constructor Create(aValue: TDateTime); overload;
  
        procedure Assign(const aSource : TNullableDateTime); overload;
        procedure Assign(const aSourceField : TField); override; overload;
        procedure Assign (const aValue: Variant); override; overload;
        procedure Assign (const aValue: String); override; overload;
        function AsVariant: Variant; override;
        function CheckIfDifferentAndAssign(const aValue: Variant): boolean; override;
  
  
negative.code:     constructor Create(aValue: Boolean); overload;
  
      procedure Assign(const aSource : TNullableBoolean); overload;
      procedure Assign(const aSourceField : TField); overload;
      procedure Assign(const aSourceField: TField; const aAllowNull: boolean); overload;
      procedure Assign (const aValue : Variant); override; overload;
      procedure Assign (const aValue : string); overload;
  
      function CheckIfDifferentAndAssign(const aValue : Variant) : boolean; override;
      function AsVariant: Variant; override;
  