func ByKey(key Key) LookupOption {
	return byKeyOption{
		Key: key,
	}
}
// ByKey returns a LookupOption that specifies a cache key to look up.
// If the object exists in the cache, the cached version will be
// returned; otherwise, the index's factory function will be called
// (unless SearchCache is also provided).
ByKey returns a LookupOption that specifies a cache key to look up.
If the object exists in the cache, the cached version will be
returned; otherwise, the index's factory function will be called
(unless SearchCache is also provided).
// ByKey returns a LookupOption that specifies a cache key to look up . // If the object exists in the cache the cached version will be // returned ; otherwise the index ' s factory function will be called // ( unless SearchCache is also provided ) .
func ByKey(key Key) LookupOption {
	return byKeyOption{
		Key: key,
	}
}
func ByKey ( key Key ) LookupOption { return byKeyOption { Key : key , } }
ByKey returns a LookupOption that specifies a cache key to look up.
ByKey returns a LookupOption that specifies a cache key to look up .