code: public static Throwable throwIfIOE(Throwable t) throws IOException {
          if (t instanceof IOException) {
              throw (IOException)t;
          }
          return t;
      }
docs: Helper method that will check if argument is an {@link IOException},
  and if so, (re)throw it; otherwise just return.
  
  @param t the Throwable to possibly propagate
  @return the Throwable
  @throws IOException rethrow the IOException