Unlock in init

attachLeaveApplication() {
    $(window).unbind('beforeunload', this.leaveApplicationHandler);
    $(window).bind('beforeunload', {context: this}, this.leaveApplicationHandler);
  }
  leaveApplicationHandler(event) {
    if (event.data.context.getAppProperty('skipUnlockOnRedirect')) {
      event.data.context.setAppProperty('skipUnlockOnRedirect', false);
      return;
    }
    event.data.context.sendInfrcUnlockSynch(event);
  };

  /**
   *
   * @param oEvent
   */
  sendInfrcUnlockSynch(oEvent) {
    const xhr = new XMLHttpRequest(), sCookie = document.cookie;
    let sapClient = '';
    sCookie.split(';').forEach((i) => {
      const aParam = i.split('=');
      // we can have more '=' in cookie parameter string e.g sap-usercontext=sap-client=n
      if (aParam[0].trim() === 'sap-usercontext') {
        sapClient = i.substring(i.indexOf(aParam[1]));
      }
    });
    const sGuid = jQuery.sap.encodeURL(`'${this._guid}'`);
    xhr.open('POST', `${this._oModel.sServiceUrl}/InfrcUnlock?${sapClient}&Guid=${sGuid}`, true);
    xhr.setRequestHeader('x-csrf-token', this._oModel.getSecurityToken());
    xhr.send();
  }