Org.BouncyCastle.Pkix.PkixNameConstraintValidator.unionDNS C# (CSharp) Метод

        protected ISet unionDNS(ISet excluded, String dns)
        {
            if (excluded.IsEmpty)
            {
                if (dns == null)
                {
                    return excluded;
                }
                excluded.Add(dns);

                return excluded;
            }
            else
            {
                ISet union = new HashSet();

                IEnumerator _iter = excluded.GetEnumerator();
                while (_iter.MoveNext())
                {
                    String _permitted = (String)_iter.Current;

                    if (WithinDomain(_permitted, dns))
                    {
                        union.Add(dns);
                    }
                    else if (WithinDomain(dns, _permitted))
                    {
                        union.Add(_permitted);
                    }
                    else
                    {
                        union.Add(_permitted);
                        union.Add(dns);
                    }
                }

                return union;
            }
        }