code: public static PhoneNumber create(final BandwidthClient client, final Map<String, Object> params) throws Exception {
          final String uri = client.getUserResourceUri(BandwidthConstants.PHONE_NUMBER_URI_PATH);
          final RestResponse createResponse = client.post(uri, params);
          final RestResponse getResponse = client.get(createResponse.getLocation(), null);
          final JSONObject jsonObject = toJSONObject(getResponse);
          return new PhoneNumber(client, jsonObject);
      }
docs: Factory method to allocate a phone number given a set of params. Note that this assumes that the phone number
  has been previously search for as an AvailableNumber
  @param client the client
  @param params the params
  @return the PhoneNumber
  @throws IOException unexpected error.