code: private File[] resolveConfigFiles(File base, Map<String, Object> override) {
          //system properties
          //-Dconfig=config.json -> override
          //Override
          if (override != null) {
              String configFilesString = (String) override.remove("config");
              if (StringUtils.isNotBlank(configFilesString)) {
                  log.info("Using config files: {}", configFilesString);
  
                  String[] strings = StringUtils.split(configFilesString, ',');
                  File[] files = new File[strings.length];
                  for (int i = 0; i < strings.length; i++) {
                      files[i] = new File(base, strings[i]);
                  }
                  return files;
              }
          }
  
          //default
          useDefaultConfigFiles = true;
          return base.listFiles(DEFAULT_CONFIG_FILES_FILTER);
      }
docs: Find all config files.
  
  @param base     site base site
  @param override command options, system properties, etc.
  @return