code: public void connect(String eventSourceUrl) throws IOException {
          LOG.entering(CLASS_NAME, "connect", eventSourceUrl);
          if (stream != null) {
              LOG.warning("Reusing the same event source for a differnt URL, please create a new EventSource object");
              throw new IllegalArgumentException(
                      "Reusing the same event source for a differnt URL, please create a new EventSource object");
          }
          stream = new SseEventStream(eventSourceUrl);
          stream.setListener(eventStreamListener);
          stream.connect();
      }
docs: Connects the EventSource instance to the stream location.
  
  @param eventSourceUrl
  stream location
  @throws IOException
  on error