@Override
  @SuppressWarnings("UnsynchronizedOverridesSynchronized") // no need to synchronize to return null
  protected @Nullable InetAddress getHostAddress(URL url) {
    // jimfs uses the URI host to specify the name of the file system being used.
    // In the default implementation of getHostAddress(URL), a non-null host would cause an attempt
    // to look up the IP address, causing a slowdown on calling equals/hashCode methods on the URL
    // object. By returning null, we speed up equality checks on URL's (since there isn't an IP to
    // connect to).
    return null;
  }
@deprecated Not intended to be called directly; this class is only for use by Java itself.
jimfs/src/main/java/com/google/common/jimfs/Handler.java