class SearchResults extends FragmentsArray<SearchResult> {
     discountedResults(): SearchResults<SearchResult> {
            return this.filter(result => result.isDiscounted())
     }
}

class SearchResult extends Fragment {
    isDiscounted() {
         return this.$(‘.discountlabel’).isDisplayed()
    }

    price() {
         return this.$(‘.price’)
    }
}

const results = new SearchResults($$(‘div.results’))

results.length // native array methods supported

const discounted = results.discountedResults() // as well as additional own methods 

discounted[0].price() // each element of array is instance of SearchResult with additional methods, not just raw WebElement