is(uri, haystack_url = window.location.pathname) {
    uri = this.modifyURI(uri);
    const original_segments = haystack_url.split('/');
    const route_segments = uri.split('/');
    const original_length = original_segments.length;
    const route_length = route_segments.length;
    if (original_length !== route_length) {
      return false;
    }
    for (let i = 1; i < original_length; i++) {
      if (route_segments[i].indexOf('{') === -1 && route_segments[i] !== original_segments[i]) {
        return false;
      }
    }
    return true;
  }
Check if current URL is attached to route (1st param)
or if second optional param passed - checks against haystack_url not current URL
@param uri
@param haystack_url
@returns {boolean}