public class UnitXmlConstructor : IEntityXmlConstructor
{
    private readonly IHandbooksService _handbooksService;
    public UnitXmlConstructor(IHandbooksService handbooksService)
    {
        _handbooksService = handbooksService;
    }

    public async Task<XElement> Construct(string id)
    {
        var units = _handbooksService.GetUnitsList(0, -1, null);
        var unit = units.Data.FirstOrDefault(c => c.Code == id);
        return new XElement("root",
            new XAttribute("Code", unit?.Code ?? ""),
            new XAttribute("Name", unit?.UnitName ?? ""));
    }
}

public class BoolXmlConstructor : IEntityXmlConstructor
{
    public BoolXmlConstructor()
    {
    }

    public async Task<XElement> Construct(string value, object parameter)
    {
        bool logicValue = false;
        bool.TryParse(value, out logicValue);
        return new XElement("root",
            new XText(logicValue ? parameter?.ToString() ?? "" : ""));
    }
}