What is the method used to obtain the "Time-Cached" information from the response returned through the cache.match(req) function in the CacheStorage API?

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The "Time-Cached" information is not obtained directly from the response returned through the cache.match(req) function in the CacheStorage API. It is typically calculated by the application developer by comparing the current time with the time when the response was first cached. One way to do this is by including a custom header in the response (e.g. "X-Cache-Date") that contains the time when the response was initially stored in the cache. The application can then retrieve this header value from the response object and calculate the time difference. Another approach is to include a timestamp in the response URL, which can be used to determine the time when the response was first cached.