code: public static String getStringExtends(Configuration config, String module) {
          Map<String, Object> map = config.getProperties();
          String extension = (String) map.get(AbstractTemplateProcessor.TEMPLATE_CONF_PREFIX + module + ".suffix");
          if (StringUtils.isNotBlank(extension)) {
              extension = StringUtils.deleteWhitespace(extension);
          }
  
          if (StringUtils.isBlank(extension)) {
              extension = (String) map.get(AbstractTemplateProcessor.TEMPLATE_CONF_PREFIX + "suffix");
              if (StringUtils.isNotBlank(extension)) {
                  extension = StringUtils.deleteWhitespace(extension);
              }
          }
  
          return StringUtils.isBlank(extension) ? null : extension.toLowerCase();
      }
docs: <p>getStringExtends.</p>
  
  @param config a {@link javax.ws.rs.core.Configuration} object.
  @param module a {@link java.lang.String} object.
  @return a {@link java.lang.String} object.