public static List<String> patternsToBaseDns(Collection<String> patterns) {
    List<String> result = new ArrayList<>();
    for (String pattern : patterns) {
      result.add(patternToBaseDn(pattern));
    }
    return result;
  }
Converts a collection of Distinguished Name patterns to a collection of base DNs.
@param patterns Distinguished Name patterns
@return a list of base DNs
@see MetastoreConf.ConfVars#METASTORE_PLAIN_LDAP_GROUPDNPATTERN
@see MetastoreConf.ConfVars#METASTORE_PLAIN_LDAP_USERDNPATTERN
standalone-metastore/metastore-common/src/main/java/org/apache/hadoop/hive/metastore/ldap/LdapUtils.java