public async Task UpdateFamilyAsync(Family fam)
        {
            if (!families.Any())
            {
                families = await GetAllFamiliesAsync();
            }

            foreach (var family in families)
            {
                if (family.StreetName.Equals(fam.StreetName) && family.HouseNumber == fam.HouseNumber)
                {
                    family.EditFamily(fam);
                }
            }

            await WriteFamiliesToFile();
        }
 public async Task AddFamilyAsync(Family family)
 {
     // the validation has been done by the controller right?
     families.Add(family);
     await WriteFamiliesToFile();
 }