code: function bindProperties() {
    let sortDirection;
  
    Object.defineProperty( this, 'sortDirection', {
      configurable: true,
      get: function() {
        return sortDirection;
      },
      set: function( value ) {
        if ( value === DIRECTIONS.UP ) {
          this.sortClass = this.classes.sortUp;
        } else if ( value === DIRECTIONS.DOWN ) {
          this.sortClass = this.classes.sortDown;
        }
        sortDirection = value;
      }
    } );
  }
docs: Function used to create computed and trigger properties.