code: public void initialize(URI path, Configuration config, boolean initSuperclass)
        throws IOException {
      long startTime = System.nanoTime();
      Preconditions.checkArgument(path != null, "path must not be null");
      Preconditions.checkArgument(config != null, "config must not be null");
      Preconditions.checkArgument(path.getScheme() != null, "scheme of path must not be null");
      if (!path.getScheme().equals(getScheme())) {
        throw new IllegalArgumentException("URI scheme not supported: " + path);
      }
      initUri = path;
      logger.atFine().log("GHFS.initialize: %s", path);
  
      if (initSuperclass) {
        super.initialize(path, config);
      } else {
        logger.atFine().log(
            "Initializing 'statistics' as an instance not attached to the static FileSystem map");
        // Provide an ephemeral Statistics object to avoid NPE, but still avoid registering a global
        // statistics object.
        statistics = new Statistics(getScheme());
      }
  
      // Set this configuration as the default config for this instance; configure()
      // will perform some file-system-specific adjustments, but the original should
      // be sufficient (and is required) for the delegation token binding initialization.
      setConf(config);
  
      // Initialize the delegation token support, if it is configured
      initializeDelegationTokenSupport(config, path);
  
      configure(config);
  
      long duration = System.nanoTime() - startTime;
      increment(Counter.INIT);
      increment(Counter.INIT_TIME, duration);
    }
docs: Initializes this file system instance.
  
  Note:
  The path passed to this method could be path of any file/directory.
  It does not matter because the only thing we check is whether
  it uses 'gs' scheme. The rest is ignored.
  
  @param path URI of a file/directory within this file system.
  @param config Hadoop configuration.
  @param initSuperclass if false, doesn't call super.initialize(path, config); avoids
  registering a global Statistics object for this instance.