code: private boolean isFallbackPossible(SSLSocket socket) {
      for (int i = nextModeIndex; i < connectionSpecs.size(); i++) {
        if (connectionSpecs.get(i).isCompatible(socket)) {
          return true;
        }
      }
      return false;
    }
docs: Returns {@code true} if any later {@link ConnectionSpec} in the fallback strategy looks
  possible based on the supplied {@link SSLSocket}. It assumes that a future socket will have the
  same capabilities as the supplied socket.