selectedRange() {
    const caret = this._needsManualCaret ?
        this._manualCaret :
        getCaret(this.element);

    return {
      start: caret.start,
      length: caret.end - caret.start
    };
  }
Gets the range of the current selection.

@augments external:InputSim.Input#selectedRange
@returns {Object} {start: number, length: number}