Issue #342: CacheResponse race condition with has and get

[swichers]

• Issue Cache is becoming invalidated between calls has() and get() #342: Resolve issue with has/get race condition
• Issue Cache is becoming invalidated between calls has() and get() #342: Align more closely with original code

[freekmurze]

Could you summarise why this change is needed?

[swichers]

Discussion #342 goes into explicit detail.

#342 (comment)

There is a race condition when calling hasBeenCached and getCachedResponseFor.

hasBeenCached can return true and the cache can clear/expire before getCachedResponseFor is called, which then triggers an exception.

Technically this hasBeenCached call is redundant/less performant since it winds up doing a get() anyway ( #342 (reply in thread) ). I left it in place to minimize changes.

[freekmurze]

Thank you for hunting down this bug!