clock
Sets the clock used to:
compute the expiration date (see storeExpirationDate)
get the received date (see com.apollographql.cache.normalized.options.storeReceivedDate)
comparing these dates to the current time in com.apollographql.cache.normalized.api.CacheControlCacheResolver
This is useful for testing purposes only.
Parameters
clock
returns the current time in milliseconds since the epoch.