Returns users as XML. Content-Type: application/xml.

<users>
  <user>
    <id>1</id>
    <name>John Doe</name>
    <email>john@example.com</email>
    <age>30</age>
    <city>New York</city>
  </user>
  ...
</users>

Returns products as XML with flat structure (no nested objects).

<products>
  <product>
    <id>1</id>
    <name>Laptop Pro</name>
    <price>1299.99</price>
    <category>electronics</category>
    ...
  </product>
  ...
</products>