throw new IllegalArgumentException("unknown object in factory");
throw new IllegalArgumentException("unknown object in factory: " + obj.getClass().getName());
    public static ContentInfo getInstance(        Object  obj)    {        if (obj instanceof ContentInfo)        {            return (ContentInfo)obj;        }        else if (obj instanceof ASN1Sequence)        {            return new ContentInfo((ASN1Sequence)obj);        }        throw new IllegalArgumentException("unknown object in factory");    }