Inheritance: ICondition
 public void ConditionWithTrueExpression_ShouldBeFulfilled()
 {
     var condition = new Condition().WithExpression(() => true);
     condition.Validate().ShouldBeEquivalentTo(ConditionState.Fulfilled);
 }
 public void ConditionWithNotfulfilledExpression_ShouldBeNotFulfilled()
 {
     var condition = new Condition().WithExpression(() => ConditionState.NotFulfilled);
     condition.Validate().ShouldBeEquivalentTo(ConditionState.NotFulfilled);
 }