Method MaybeRefreshBlocking

You must call this (or MaybeRefresh()), periodically, if you want that Acquire() will return refreshed instances.

Threads: unlike MaybeRefresh(), if another thread is currently refreshing, this method blocks until that thread completes. It is useful if you want to guarantee that the next call to Acquire() will return a refreshed instance. Otherwise, consider using the non-blocking MaybeRefresh().