SingletonStore is a delegating cache store used for situations when only one instance in a
cluster should interact with the underlying store. The coordinator of the cluster will be
responsible for the underlying CacheStore. SingletonStore is a simply facade to a real
CacheStore implementation. It always delegates reads to the real CacheStore.
If true, purges this cache store when it starts up.
If true, fetch persistent state when joining a cluster. If multiple cache stores are chained,
only one of them can have this property enabled. Persistent state transfer with a shared cache
store does not make sense, as the same persistent store that provides the data will just end
up receiving it. Therefore, if a shared cache store is used, the cache will not allow a
persistent state transfer even if a cache store has this property set to true. Finally,
setting it to true only makes sense if in a clustered environment, and only 'replication' and
'invalidation' cluster modes are supported.
If true, any operation that modifies the cache (put, remove, clear, store...etc) won't be
applied to the cache store. This means that the cache store could become out of sync with the