public void Person_ReceiveMessage_CannotAddSelf()
{
var person = new Person("person1");
Action act = () => person.BecomeFriendWith(person);
act.ShouldThrow<ArgumentException>();
}
public void Person_CanBecomeFriend_thenBiDirectionalRelationship()
{
var person1 = new Person("person1");
var person2 = new Person("person2");
person1.BecomeFriendWith(person2);
person1.Friends.Should().Contain(person2);
person2.Friends.Should().Contain(person1);
}
