docs: public List<ContactTokenDetails> getContacts(Set<String> e164numbers)
        throws IOException
    {
      Map<String, String>       contactTokensMap = createDirectoryServerTokenMap(e164numbers);
      List<ContactTokenDetails> activeTokens     = this.pushServiceSocket.retrieveDirectory(contactTokensMap.keySet());
  
      for (ContactTokenDetails activeToken : activeTokens) {
        activeToken.setNumber(contactTokensMap.get(activeToken.getToken()));
      }
  
      return activeTokens;
    }