public void DeletePersonReturnsNotFoundWhenPersonIsNotFound()
{
Person person = null;
_personRepositoryMock.Setup(m => m.GetById(It.IsAny <int>()))
.Returns(person);
var result = _sut.DeleteEntity(1) as NotFoundObjectResult;
Assert.That(result, Is.Not.Null);
_personRepositoryMock.Verify(m => m.GetById(It.IsAny <int>()), Times.Once);
_personRepositoryMock.Verify(m => m.Remove(It.IsAny <Person>()), Times.Never);
}