How to use the @uipath/angular/testing.EventGenerator.keyDown function in @uipath/angular

it('should increment negatively if DIRECTION is UP and NAVIGATING UP', () => {
            component.direction = 'up';

            fixture.detectChanges();
            const display = fixture.debugElement.query(By.css('.display'));
            display.nativeElement.dispatchEvent(
                EventGenerator.keyDown(Key.Enter),
            );

            const itemContainer = fixture.debugElement.query(By.css('.item-list-container'));

            itemContainer.nativeElement.dispatchEvent(
                EventGenerator.keyDown(Key.ArrowUp),
            );

            expect(uiSuggest.activeIndex).toEqual(items.length - 2);
        });

it('should have circular active index (reset to first if reached the end)', () => {
            fixture.detectChanges();
            const display = fixture.debugElement.query(By.css('.display'));
            display.nativeElement.dispatchEvent(
                EventGenerator.keyDown(Key.Enter),
            );

            const itemContainer = fixture.debugElement.query(By.css('.item-list-container'));

            const keyDownPresses = items.length + 1;

            expect(uiSuggest.activeIndex).toEqual(0);

            for (let i = 1; i < keyDownPresses; i++) {
                itemContainer.nativeElement.dispatchEvent(
                    EventGenerator.keyDown(Key.ArrowDown),
                );
                expect(uiSuggest.activeIndex).toEqual(i < items.length ? i : 0);
            }
        });

const display = fixture.debugElement.query(By.css('.display'));
                display.nativeElement.dispatchEvent(EventGenerator.click);
                fixture.detectChanges();

                const searchInput = fixture.debugElement.query(By.css('.mat-input-element')).nativeElement;
                searchInput.value = randomString;
                searchInput.dispatchEvent(EventGenerator.input());
                fixture.detectChanges();
                await fixture.whenStable();

                const [query] = sourceSpy.calls.mostRecent().args;
                expect(query).toBe(randomString);

                const itemContainer = fixture.debugElement.query(By.css('.item-list-container'));
                itemContainer.nativeElement.dispatchEvent(
                    EventGenerator.keyDown(Key.Enter),
                );
                fixture.detectChanges();

                expect(uiSuggest.value[0].text).toBe(randomString);
            }));

[Key.ArrowUp, Key.ArrowDown, Key.Tab].forEach(key => {
                    itemContainer.nativeElement.dispatchEvent(
                        EventGenerator.keyDown(key),
                    );
                    fixture.detectChanges();
                    tick();
                });

searchInput.dispatchEvent(new Event('input'));
                fixture.detectChanges();
                tick(SEARCH_DEBOUNCE);

                const customItem = fixture.debugElement.query(By.css('.custom-item'));

                expect(uiSuggest.items.length).toBeGreaterThan(0);
                expect(!!customItem).toBe(true);

                const itemContainer = fixture.debugElement.query(By.css('.item-list-container'));
                itemContainer.nativeElement.dispatchEvent(
                    EventGenerator.keyDown(Key.ArrowUp),
                );

                itemContainer.nativeElement.dispatchEvent(
                    EventGenerator.keyDown(Key.Tab),
                );
                fixture.detectChanges();
                tick(VIRTUAL_SCROLL_DEBOUNCE);

                expect(uiSuggest.value.length).toBe(0);

                discardPeriodicTasks();
            }));