public static MainRecord ToEntity(this MainDto dto)
{
if (dto == null) return null;
var entity = new MainRecord();
entity.Id = dto.key;
entity.ParentId = dto.parentId;
entity.Title = dto.title;
entity.MainTypeRecord = dto.mainType.ToEntity();
dto.OnEntity(entity);
return entity;
}
partial static void OnEntity(this MainDto dto, MainRecord entity);