code: public static PhoneNumber get(final BandwidthClient client, final String phoneNumberId) throws Exception {
          assert(client != null && phoneNumberId != null);
          final String phoneNumberUri = client.getUserResourceInstanceUri(BandwidthConstants.PHONE_NUMBER_URI_PATH, phoneNumberId);
          final JSONObject phoneNumberObj = toJSONObject(client.get(phoneNumberUri, null));
          final PhoneNumber number = new PhoneNumber(client, phoneNumberObj);
          return number;
      }
docs: Factory method for PhoneNumber. Returns PhoneNumber object
  @param client the client
  @param phoneNumberId the phone number id
  @return the PhoneNumber
  @throws IOException unexpected error.