KIF + Swift reset/restart app

Question

I'm developing automated tests using KIF and Swift
I wrote some tests but they don't depend on each other
How to reset app and execute this in beforeEach() method?

class PassengerCountTests: KIFTestCase {

enum Element: String {
    case passengerCount = "passengerCount_label"
    case plusButton = "plus_button"
    case minusButton = "minus_button"

}

func getElement(element: Element) -> UIView {
    return tester().waitForView(withAccessibilityLabel: element.rawValue)
}

func tap(element: Element) {
    tester().tapView(withAccessibilityLabel: element.rawValue)
}


func testMinPassengerNumber() {
    let passengerCount = getElement(element: Element.passengerCount)
    let minusButton = getElement(element: Element.minusButton)

    XCTAssertEqual(passengerCount.accessibilityValue, "1")
    XCTAssertEqual(minusButton.isProbablyTappable, false)
}

func testMaxPassengerNumber() {
    for _ in 1...4 {
        tap(element: Element.plusButton)
    }

    let passengerCount = getElement(element: Element.passengerCount)
    let plusButton = getElement(element: Element.plusButton)

    XCTAssertEqual(passengerCount.accessibilityValue, "5")
    XCTAssertEqual(plusButton.isProbablyTappable, false)
}

}