function _sendSessionUpdate() {
  const isolationScope = hub.getIsolationScope();
  const currentScope = getCurrentScope();
  const client = getClient();
  // TODO (v8): Remove currentScope and only use the isolation scope(?).
  // For v7 though, we can't "soft-break" people using getCurrentHub().getScope().setSession()
  const session = currentScope.getSession() || isolationScope.getSession();
  if (session && client && client.captureSession) {
    client.captureSession(session);
  }
}
Sends the current Session on the scope