getSub = function () {
            var ret = [];
            if (len !== null) {
                // definite length
                var end = start + len;
                while (stream.pos < end) {
                    ret[ret.length] = ASN1.decode(stream);
                }
                if (stream.pos != end) {
                    throw new Error("Content size is not correct for container starting at offset " + start);
                }
            }
            else {
                // undefined length
                try {
                    for (;;) {
                        var s = ASN1.decode(stream);
                        if (s.tag.isEOC()) {
                            break;
                        }
                        ret[ret.length] = s;
                    }
                    len = start - stream.pos; // undefined lengths are represented as negative values
                }
                catch (e) {
                    throw new Error("Exception while decoding undefined length content: " + e);
                }
            }
            return ret;
        }
Retrieve the hexadecimal value (as a string) of the current ASN.1 element
@returns {string}
@public