docs: private File expandScriptPlugin(final File file) throws IOException {
          if (!cachedir.exists()) {
              if (!cachedir.mkdirs()) {
                  log.warn("Unable to create cache dir: " + cachedir.getAbsolutePath());
              }
          }
          final File jardir = getFileCacheDir();
          if (!jardir.exists()) {
              if (!jardir.mkdir()) {
                  log.warn("Unable to create cache dir for plugin: " + jardir.getAbsolutePath());
              }
          }
          final String prefix = getFileBasename() + "/contents";
  
          debug("Expand zip " + file.getAbsolutePath() + " to dir: " + jardir + ", prefix: " + prefix);
          ZipUtil.extractZip(file.getAbsolutePath(), jardir, prefix, prefix + "/");
  
          return jardir;
      }