Creates a continuous source of ServerSentEvents from the given URI and streams it into the given handler.
Creates a continuous source of ServerSentEvents from the given URI and streams it into the given handler. Once a source of ServerSentEvents obtained via the connection is completed, a next one is obtained thereby sending the Last-Evend-ID header if there is a last event id.
URI with absolute path, e.g. "http://myserver/events
handler for ServerSentEvents
initial value for Last-Evend-ID header, optional
delay before obtaining the next source from the URI
implicit ExecutionContext
implicit Materializer
source of materialized values of the handler