return input.readDouble();
      } catch (IOException e) {
        throw new IllegalStateException(e);
      }
    }

    @Override
    @CheckForNull
    public String readLine() {
      try {
        return input.readLine();
      } catch (IOException e) {
        throw new IllegalStateException(e);
      }
    }

    @Override
    public String readUTF() {
      try {