As far as I understand this functionality is now implemented in base repository https://github.com/microsoft/BotFramework-DirectLineJS under a new class DirectLine.DirectLineStreaming. But the link from documentation is still pointing to this repo. Please confirm my understanding and remove this repository and the link as it is confusing.
Documentation link: https://docs.microsoft.com/en-us/azure/bot-service/bot-service-channel-directline-extension-webchat-client?view=azure-bot-service-4.0