code: public static String getPlatform(RemoteProxy proxy) {
      if (proxy.getTestSlots().size() == 0) {
        return "Unknown";
      }
      Platform res = getPlatform(proxy.getTestSlots().get(0));
  
      for (TestSlot slot : proxy.getTestSlots()) {
        Platform tmp = getPlatform(slot);
        if (tmp != res) {
          return "mixed OS";
        }
        res = tmp;
      }
      if (res == null) {
        return "not specified";
      }
      return res.toString();
    }
docs: return the platform for the proxy. It should be the same for all slots of the proxy, so checking that.
  @param proxy remote proxy
  @return Either the platform name, "Unknown", "mixed OS", or "not specified".