The starting point of any request is to verify that the object we want to access exists.
In this example, we want to add a ticket for a parking session. We need to know if a ticket for the vehicle already exists in the Park.
•If so, we may want to extend the ticket using the ADD word.
•If no ticket is found, we can create one using the POST word
Other words are available, as we will see in the first request we send.
