code: public static Option configurationFolder(File folder, String extension) {
          if (!folder.exists()) {
              throw new TestContainerException("folder " + folder + " does not exits");
          }
          List<Option> options = new ArrayList<Option>();
          File[] files = folder.listFiles();
  
          for (File file : files) {
              if (file.isDirectory()) {
                  continue;
              }
              String name = file.getName();
              if (!name.endsWith(extension)) {
                  continue;
              }
              else {
                  name = name.substring(0, name.length() - extension.length());
              }
              String[] split = name.split("-");
              org.ops4j.pax.exam.cm.internal.ConfigurationProvisionOption cfg = new org.ops4j.pax.exam.cm.internal.ConfigurationProvisionOption(split[0],
                  new HashMap<String, Object>());
              cfg.factory(split.length > 1);
              Properties properties = new Properties();
              try {
                  FileInputStream stream = new FileInputStream(file);
                  try {
                      properties.load(stream);
                  }
                  finally {
                      stream.close();
                  }
              }
              catch (IOException e) {
                  throw new TestContainerException("can't read configuration file " + file, e);
              }
              Set<String> names = properties.stringPropertyNames();
              for (String key : names) {
                  cfg.put(key, properties.getProperty(key));
              }
              options.add(cfg.asOption());
          }
          return CoreOptions.composite(options.toArray(new Option[0]));
      }
docs: read all configuration files from a folder and transform them into configuration options
  
  @param folder
  folder containing configuration files
  @param extension
  the file extension to scan for (eg .cfg)
  @return an option containing all the read configurations