public static SignedDataParser GetInstance(
object o)
{
if (o is Asn1Sequence)
return new SignedDataParser(((Asn1Sequence)o).Parser);
if (o is Asn1SequenceParser)
return new SignedDataParser((Asn1SequenceParser)o);
throw new IOException("unknown object encountered: " + o.GetType().Name);
}