constructor(blockSizeInBytes: Int = 512, flushThresholdInBytes: Int = 10240, flushThresholdInRequests: Int = 10, priorityRatio: Int = 3, prefetchTransferThresholdInBytes: Int = 8192, missingGroupBehaviour: Js5Configuration.Js5MissingGroupBehaviour = Js5MissingGroupBehaviour.DROP_REQUEST)