private val loadingLinks: Cache<String, Boolean> = CacheBuilder.newBuilder().build()
private val failureCache: Cache<String, Boolean> = CacheBuilder.newBuilder().ticker(ticker).expireAfterWrite(30, MINUTES).build()
private val elementCache: Cache<String, LinkedElement> = CacheBuilder.newBuilder().build()
private val loadingLinks: Cache<String, Boolean> = CacheBuilder.newBuilder().build()
private val failureCache: Cache<String, Boolean> = CacheBuilder.newBuilder().ticker(ticker).expireAfterWrite(30, MINUTES).build()
private val elementCache: Cache<String, LinkedElement> = CacheBuilder.newBuilder().build()