"""
    Create an invoice.

    This will (let's imagine) let the API user (some external developer) create an
    invoice.

    And this path operation will:

    * Send the invoice to the client.
    * Collect the money from the client.
    * Send a notification back to the API user (the external developer), as a callback.
        * At this point is that the API will somehow send a POST request to the

                    "description": 'Create an invoice.\n\nThis will (let\'s imagine) let the API user (some external developer) create an\ninvoice.\n\nAnd this path operation will:\n\n* Send the invoice to the client.\n* Collect the money from the client.\n* Send a notification back to the API user (the external developer), as a callback.\n    * At this point is that the API will somehow send a POST request to the\n        external API with the notification of the invoice...