code: public Object postRequest(String restUrl, Map<String, String> params) throws IOException, WebServiceException {
  		return this.postRequest(HttpMethod.POST, restUrl, params);
  	}
docs: Do a POST HTTP request to the given REST-URL.
  
  @param restUrl
  REST URL.
  @param params
  Parameters for adding to the query string.
  @throws IOException
  if the request go bad.