code: static List<Header> createHeaders(int numHeaders, int nameLength, int valueLength, boolean limitToAscii) {
          List<Header> headers = new ArrayList<Header>(numHeaders);
          Random r = new Random();
          for (int i = 0; i < numHeaders; ++i) {
              byte[] name = randomBytes(new byte[nameLength], limitToAscii);
              byte[] value = randomBytes(new byte[valueLength], limitToAscii);
              headers.add(new Header(name, value));
          }
          return headers;
      }
docs: Creates a number of random headers with the given name/value lengths.