code: public boolean hasUnsupportedCriticalExtension() {
          if (info == null)
              return false;
          try {
              CertificateExtensions exts = (CertificateExtensions)info.get(
                                           CertificateExtensions.NAME);
              if (exts == null)
                  return false;
              return exts.hasUnsupportedCriticalExtension();
          } catch (Exception e) {
              return false;
          }
      }
docs: Return true if a critical extension is found that is
  not supported, otherwise return false.