return null;
log.exiting(this.getClass().getName(), "getCertificate", result); return result;
  public Certificate getCertificate(String alias)  {    if (!containsAlias(alias))      {        return null;      }    List l = get(alias);    for (Iterator it = l.iterator(); it.hasNext();)      {        Entry e = (Entry) it.next();        if (e instanceof CertificateEntry)          {            return ((CertificateEntry) e).getCertificate();          }      }    return null;  }