public async Task ContainsEntityWithMacAsync_WhenCalled_ReturnsTrue() { // Arrange MockDeviceRepository.Setup(repository => repository.ContainsEntityWithMAC("1111", new CancellationToken(false))) .ReturnsAsync(() => true); // Act var result = await _deviceService.ContainsEntityWithMACAsync("1111", CancellationToken.None); // Assert Assert.True(result); }