internal override void Encode(
     DerOutputStream  derOut)
 {
     if (derOut is Asn1OutputStream || derOut is BerOutputStream)
     {
         derOut.WriteByte(Asn1Tags.Null);
     }
     else
     {
         base.Encode(derOut);
     }
 }
        internal override void Encode(
            DerOutputStream derOut)
        {
            if (derOut is Asn1OutputStream || derOut is BerOutputStream)
            {
                derOut.WriteByte(Asn1Tags.Constructed | Asn1Tags.OctetString);

                derOut.WriteByte(0x80);

                //
                // write out the octet array
                //
                foreach (DerOctetString oct in this)
                {
                    derOut.WriteObject(oct);
                }

                derOut.WriteByte(0x00);
                derOut.WriteByte(0x00);
            }
            else
            {
                base.Encode(derOut);
            }
        }