public async Task <ActionResult <Company> > Put(int id, [FromBody] CompanyDTO request)
        {
            var company = await _service.GetByIdAsync(id);

            await _service.DeletePrefixesByCompanyAsync(company);

            company.Name     = request.Name;
            company.Prefixes = request.Prefixes.Select(p => new Prefix {
                Number = p.Number
            }).ToList();

            _db.Entry(company).State = EntityState.Modified;
            await _db.SaveChangesAsync();

            return(Ok(company));
        }