code: private void buildHeaders() {
  		if (!headers.isEmpty()) {
  			for (Map.Entry<String, List<String>> entry : headers.entrySet()) {
  				List<String> values = entry.getValue();
  
  				for (String value : values) {
  					connection.addRequestProperty(entry.getKey(), value);
  				}
  			}
  		}
  	}
docs: A private method that loops through the headers Map, putting them on the Request or Response object.