public void ChangeStatus_NullFormulaTest()
        {
            //Arrange
            IFormulaStatusManager statusManager = new FormulaStatusManager();

            //Act
            //Assert
            Assert.ThrowsException <ArgumentNullException>(() => statusManager.ChangeStatus(null, FormulaStatus.Deleted));
        }
        public void ChangeStateTest()
        {
            //Arrange
            IFormulaStatusManager statusManager = new FormulaStatusManager();
            var formula = new ServerFormula()
            {
                Status = FormulaStatus.Success
            };
            var newStatus = FormulaStatus.Deleted;
            //Act
            var notifier = statusManager.ChangeStatus(formula, newStatus);

            //Assert
            Assert.AreEqual(newStatus, formula.Status);
            Assert.IsNotNull(notifier);
        }