_setAffectedValue(affectedValue) {
      this._valueAffected = affectedValue;
      // If the values have been swapped reset the reversed flag
      if (this._areValuesReversed()) {
        this._setValuesAreReversed();
      }
    }
Sets the value property (start/end) that will get updated
by a user action depending on that user action's characteristics
- mouse press position - cursor coordinates relative to the start/end handles
- selected inner element via a keyboard navigation

@param {string} affectedValue The value that will get modified by the interaction
@private