        XCTAssertEqual(unit, EnergyFormatter.Unit.calorie)
        
        XCTAssertEqual(formatter.unitString(fromJoules: 4185, usedUnit: &unit), "kcal")
        XCTAssertEqual(unit, EnergyFormatter.Unit.kilocalorie)
        
        XCTAssertEqual(formatter.unitString(fromJoules: 100000, usedUnit: &unit), "kcal")
        XCTAssertEqual(unit, EnergyFormatter.Unit.kilocalorie)
        
        formatter.numberFormatter.locale = Locale(identifier: "de_DE")
        XCTAssertEqual(formatter.unitString(fromJoules: -100000, usedUnit: &unit), "kJ")
        XCTAssertEqual(unit, EnergyFormatter.Unit.kilojoule)