code: private String getServerType(final PlexusConfiguration configuration) {
          final Pattern pattern = Pattern.compile("\\$\\{[A-Za-z0-9\\._]+\\}");
          for (final PlexusConfiguration cfg : configuration.getChildren()) {
              if (cfg.getName().equals(SERVER_TYPE_ATTRIBUTE)) {
                  if (pattern.matcher(cfg.getValue()).matches()) {
                      return DEFAULT_SERVER_TYPE_VALUE;
                  } else {
                      return cfg.getValue();
                  }
              }
          }
          return DEFAULT_SERVER_TYPE_VALUE;
      }
docs: Determine the configured LDAP server type. If one has not been configured then
  return the default.
  
  @param configuration The plugin configuration.
  @return The LDAP server type.