docs: public static String file(File file) throws IOException {
          FileInputStream fi = null;
          try {
              fi = new FileInputStream(file);
              return stream(fi, file.length());
          } finally {
              if (fi != null) {
                  try {
                      fi.close();
                  } catch (Throwable t) {
                  }
              }
          }
  
      }