function checkReachabilityEvents(reqMade, reqSucceeded, reqFail, backChannel) {
  assertEquals(
      reqMade, reachabilityEvents[ServerReachability.REQUEST_MADE] || 0);
  assertEquals(
      reqSucceeded,
      reachabilityEvents[ServerReachability.REQUEST_SUCCEEDED] || 0);
  assertEquals(
      reqFail, reachabilityEvents[ServerReachability.REQUEST_FAILED] || 0);
  assertEquals(
      backChannel,
      reachabilityEvents[ServerReachability.BACK_CHANNEL_ACTIVITY] || 0);
}
@suppress {visibility,checkTypes,missingProperties} suppression added to
enable type checking