The provided code snippet demonstrates the extension of a middleware script in Salesforce B2C Commerce.
Middleware scripts are used to modify or enhance the functionality of existing server-side logic, often by intercepting requests and responses to add additional processing steps or modify the response properties. In this snippet, the script adjusts caching properties (CachePeriod and cachePeriodUnit) and then calls next() to pass control to the next middleware function. The pattern of exporting module.exports alongside a custom function (applyCustomCache) adheres to the typical structure of middleware in SFCC, which extends the functionality of an existing module (in this case, indicated by module.superModule). This is characteristic of middleware extensions rather than controllers, decorators, or models.