public async Task GetById_WhenPartnerDoesNotExists_ShouldReturnNotFound()
{
// Arrange
var id = ObjectId.GenerateNewId().ToString();
_mediator.Send(Arg.Any <GetPartnerByIdQuery>()).Returns(default(Partner));
// Act
var response = await _controller.GetById(id);
// Assert
response.Should().NotBeNull().And.BeOfType <NotFoundObjectResult>();
}