The cached response payload
Timestamp when the entry was created
Absolute expiry timestamp. Infinity = never expires
End of the stale-while-revalidate window
End of the stale-if-error window
ETag header value for conditional revalidation
Last-Modified header value for conditional revalidation
Hash of Vary-relevant request headers (null = Vary:*)
Tags for group invalidation
Approximate entry size in bytes
A single entry stored in the cache with metadata and response data.