Fixing a shared parameter with partial

The API pipeline now processes endpoints dynamically, but every task instance also needs the same base URL (https://api.company.com/v2). Passing it through expand() would create a cross product of URLs and endpoints, which is not what you want. In this exercise, you'll keep the base URL constant across every mapped instance while still mapping over the endpoints: partial() fixes a parameter to one shared value, and expand() varies the rest.