code: @Override
    public void parseDirectory(File configurationDirectory) throws Exception {
      this.configurationDirectory = configurationDirectory;
      if(configurationDirectory != null && configurationDirectory.isDirectory() && configurationDirectory.canRead()) {
        Collection<File> configFiles = FileUtils.listFiles(configurationDirectory, new String[] {"yml", "yaml"}, true);
        List<File> files = new ArrayList<File>(configFiles);
        Collections.sort(files, NameFileComparator.NAME_INSENSITIVE_COMPARATOR);
        Map<String, Map<String, ?>> configurationMap = new HashMap<String, Map<String, ?>>();
        Yaml yamlParser = new Yaml(getClassTags());
        for(File configFile : files) {
          FileReader reader = null;
          try {
            reader = new FileReader(configFile);
            for(Object parsed : yamlParser.loadAll(reader)){
              mergeConfigs(configurationMap, parsed);
            }
          } finally {
            IOUtils.closeQuietly(reader);
          }
        }
        this.configuration = configurationMap;
      } else if(configurationDirectory != null && configurationDirectory.isDirectory()){
        logger.warn("Directory {} cannot be read.", configurationDirectory);
      } else if(configurationDirectory != null){
        logger.warn("Directory {} is not a directory or does not exist.", configurationDirectory);
      } else {
        throw new IllegalArgumentException("The configurationDirectory must be specified.");
      }
    }
docs: This will only parse the files with the extensions of <code>.yml</code> or <code>.yaml</code> in the directory specified.