/** {@inheritDoc} */
  public void initializeSyntax(AttributeSyntaxCfg configuration) throws ConfigException {
    defaultApproximateMatchingRule =
        DirectoryServer.getApproximateMatchingRule(AMR_DOUBLE_METAPHONE_OID);
    if (defaultApproximateMatchingRule == null) {
      logError(
          ERR_ATTR_SYNTAX_UNKNOWN_APPROXIMATE_MATCHING_RULE.get(
              AMR_DOUBLE_METAPHONE_OID, SYNTAX_PRESENTATION_ADDRESS_NAME));
    }

    defaultEqualityMatchingRule = DirectoryServer.getEqualityMatchingRule(EMR_CASE_IGNORE_OID);
    if (defaultEqualityMatchingRule == null) {
      logError(
          ERR_ATTR_SYNTAX_UNKNOWN_EQUALITY_MATCHING_RULE.get(
              EMR_CASE_IGNORE_OID, SYNTAX_PRESENTATION_ADDRESS_NAME));
    }

    defaultOrderingMatchingRule = DirectoryServer.getOrderingMatchingRule(OMR_CASE_IGNORE_OID);
    if (defaultOrderingMatchingRule == null) {
      logError(
          ERR_ATTR_SYNTAX_UNKNOWN_ORDERING_MATCHING_RULE.get(
              OMR_CASE_IGNORE_OID, SYNTAX_PRESENTATION_ADDRESS_NAME));
    }

    defaultSubstringMatchingRule = DirectoryServer.getSubstringMatchingRule(SMR_CASE_IGNORE_OID);
    if (defaultSubstringMatchingRule == null) {
      logError(
          ERR_ATTR_SYNTAX_UNKNOWN_SUBSTRING_MATCHING_RULE.get(
              SMR_CASE_IGNORE_OID, SYNTAX_PRESENTATION_ADDRESS_NAME));
    }
  }
 /**
  * Retrieves the default approximate matching rule that will be used for attributes with this
  * syntax.
  *
  * @return The default approximate matching rule that will be used for attributes with this
  *     syntax, or <CODE>null</CODE> if approximate matches will not be allowed for this type by
  *     default.
  */
 @Override
 public ApproximateMatchingRule getApproximateMatchingRule() {
   if (approximateMatchingRule == null) {
     approximateMatchingRule =
         DirectoryServer.getApproximateMatchingRule(AMR_DOUBLE_METAPHONE_OID);
   }
   return approximateMatchingRule;
 }