@Override
  public String readNonControlCharacters(int maxLength) {
    StringBuilder sb = new StringBuilder();
    while (sb.length() < maxLength) {
      Character c = myPushBackQueue.peek();
      if (c != null) {
        if (c.charValue() < 32) {
          break;
        }
        sb.append(myPushBackQueue.poll());
      }
      else {
        c = myQueue.peek();
        if (c == null || c.charValue() < 32) {
          break;
        }
        sb.append(myQueue.poll());
      }
    }

    return sb.toString();
  }
@Override
  public String readNonControlCharacters(int maxLength)