@Override
    public ParseResult parseUriPath(String uriPath) {
      checkArgument(uriPath.startsWith("/$"), "uriPath (%s) must start with /$", uriPath);
      return parsePath(uriPath.substring(1));
    }
Arbitrary path type with $ as the root, / as the separator and \ as an alternate separator.
jimfs/src/test/java/com/google/common/jimfs/PathTypeTest.java