code: private static ASN1Sequence getAltnameSequence(final List sanItem) {
          //Should not be the case, but still, a extra "safety" check
          if (sanItem.size() < 2) {
              LOGGER.error("Subject Alternative Name List does not contain at least two required elements. Returning null principal id...");
          }
          val itemType = (Integer) sanItem.get(0);
          if (itemType == 0) {
              val altName = (byte[]) sanItem.get(1);
              return getAltnameSequence(altName);
          }
          return null;
      }
docs: Get alt name seq.
  
  @param sanItem subject alternative name value encoded as a two elements List with elem(0) representing object id and elem(1)
  representing object (subject alternative name) itself.
  @return ASN1Sequence abstraction representing subject alternative name or null if the passed in
  List doesn't contain at least two elements.
  as expected to be returned by implementation of {@code X509Certificate.html#getSubjectAlternativeNames}
  @see <a href="http://docs.oracle.com/javase/7/docs/api/java/security/cert/X509Certificate.html#getSubjectAlternativeNames()">
  X509Certificate#getSubjectAlternativeNames</a>