我应该如何在Delphi中实现一个巨大但简单的索引StringList？

program SimpleIndexedStringList;

{$APPTYPE CONSOLE}

uses
  System.Generics.Collections,
  System.SysUtils;

type
  TIndexedStringList = class
  private
    FDictionary: TDictionary<string, string>;
  public
    constructor Create;
    destructor Destroy; override;
    procedure Add(const Key, Value: string);
    function GetValue(const Key: string): string;
  end;

constructor TIndexedStringList.Create;
begin
  FDictionary := TDictionary<string, string>.Create;
end;

destructor TIndexedStringList.Destroy;
begin
  FDictionary.Free;
  inherited;
end;

procedure TIndexedStringList.Add(const Key, Value: string);
begin
  FDictionary.AddOrSetValue(Key, Value);
end;

function TIndexedStringList.GetValue(const Key: string): string;
begin
  if FDictionary.TryGetValue(Key, Result) then
    Exit;
  Result := '';
end;

var
  IndexedStringList: TIndexedStringList;
begin
  IndexedStringList := TIndexedStringList.Create;
  try
    IndexedStringList.Add('key1', 'value1');
    IndexedStringList.Add('key2', 'value2');
    IndexedStringList.Add('key3', 'value3');

    WriteLn(IndexedStringList.GetValue('key1'));
    WriteLn(IndexedStringList.GetValue('key2'));
    WriteLn(IndexedStringList.GetValue('key3'));
  finally
    IndexedStringList.Free;
  end;
  ReadLn;
end.