Below is a possible solution:

$ cat myhandler.yml
---
- hosts: node2
  become: yes
  roles:
    - handlerrole

$ ansible-galaxy init roles/handlerrole

$ cat roles/handlerrole/tasks/main.yml
---
- name: create directory
  file:
    path: /home/ansible/newdir
    state: directory
  notify: timestamp

$ cat roles/handlerrole/handlers/main.yml
---
- name: create readme with timestamp
  copy:
    dest: /home/ansible/newdir/README.TXT
    content: "This folder was created at {{ ansible_date_time.iso8601 }}"
  listen: timestamp

$ ansible-playbook myhandler.yml #<-- some changes when run the first time
$ ansible-playbook myhandler.yml #<-- no changes here, idempotent!

$ cat download.yml
---
- hosts: node2
  become: yes
  roles:
    - downloader

$ ansible-galaxy init roles/downloader

$ $ cat roles/downloader/tasks/main.yml
---
# tasks file for roles/downloader
- block:
    - name: Download things from the internet
      get_url:
        url: http://www.not_existing_url.com/not_existing_file
        dest: /tmp/
  rescue:
    - debug:
        msg: "Download failed!"
  always:
    - debug:
        msg: "Download attempt finished."


$ ansible-playbook download.yml