watchUrlHash(toggle) {
    __privateSet(this, _sendUrlHash, this.truthy(toggle, __privateGet(this, _sendUrlHash) !== true));
    return __privateGet(this, _sendUrlHash);
  }
Turn on/off/toggle sending URL hash changes back to Node-RED
@param {string|number|boolean|undefined} [toggle] Optional on/off/etc
@returns {boolean} True if we will send a msg to Node-RED on a hash change