@Override
  public CharSequence subSequence(int start, int end) {
    if (end == start) {
      return "";
    } else if (start == 0 && end == 1) {
      return this;
    } else {
      throw new IndexOutOfBoundsException();
    }
  }
Returns key's corresponding Android {@code KeyEvent} code.

@return Android {@code KeyEvent} code
selendroid-server/src/main/java/io/selendroid/server/android/AndroidKeys.java