public async Task Given_CreateExam_When_ModelIsValid_Then_OkStatusCode()
{
// Arrange
var examGuid = new Guid("ef7e98df-26ed-4b21-b874-c3a2815d18ac");
var Id = Task.FromResult(examGuid);
mockRepo
.Setup(e => e.CreateNew(createExamModel))
.Returns(Id);
// Act
var Result = (OkObjectResult)await controller.CreateExam(createExamModel);
// Assert
Assert.IsType <OkObjectResult>(Result);
Assert.Equal(Id.Result, Result.Value);
}