DOCUMENTATION:
  name: urn
  author: Ansible Core
  version_added: "2.14"
  short_description: is the string a valid URN
  description:
    - Validates that the input string conforms to the URN standard.
  options:
    _input:
      description: Possible URN.
      type: string
      required: True
EXAMPLES: |
  # ISBN in URN format
  {{ 'urn:isbn:9780302376463' is urn }}
  # this is URL/URI but not URN
  {{ 'mailto://nowone@example.com' is not urn }}
RETURN:
  _value:
    description: Returns C(true) if the string is a URN and C(false) if  it is not.
    type: boolean
