code: public void downloadAndInstall() throws IOException {
          installDir.mkdirs();
  
          File tempFile = File.createTempFile("pax-exam", ".zip");
          FileOutputStream os = null;
          LOG.info("downloading {} to {}", zipUrl, tempFile);
          try {
              os = new FileOutputStream(tempFile);
              StreamUtils.copyStream(zipUrl.openStream(), os, true);
  
              LOG.info("unzipping into {}", installDir);
              ZipExploder exploder = new ZipExploder();
              exploder.processFile(tempFile, installDir);
          }
          finally {
              tempFile.delete();
          }
      }
docs: Download and unpacks the archive.
  
  @throws IOException on I/O errors