public void TestKeyEquatableEquals()
{
var sut = KeyEqualityComparer.Default;
var a1 = new MyEntity("a", "v1") as IKeyEquatable;
var a2 = new MyEntity("a", "v2") as IKeyEquatable;
var b1 = new MyEntity("b", "v1") as IKeyEquatable;
a1.KeyEquals(a2).ShouldBeEquivalentTo(true);
a2.KeyEquals(a1).ShouldBeEquivalentTo(true);
a1.KeyEquals(a1).ShouldBeEquivalentTo(true);
a2.KeyEquals(a2).ShouldBeEquivalentTo(true);
a1.KeyEquals(null).ShouldBeEquivalentTo(false);
a1.KeyEquals("!!").ShouldBeEquivalentTo(false);
b1.KeyEquals(a2).ShouldBeEquivalentTo(false);
a1.KeyEquals(b1).ShouldBeEquivalentTo(false);
sut.Equals(a1, a2).ShouldBeEquivalentTo(true);
sut.Equals(a2, a1).ShouldBeEquivalentTo(true);
sut.Equals(a1, a1).ShouldBeEquivalentTo(true);
sut.Equals(a2, a2).ShouldBeEquivalentTo(true);
sut.Equals(null, a2).ShouldBeEquivalentTo(false);
sut.Equals(a1, null).ShouldBeEquivalentTo(false);
sut.Equals(null, null).ShouldBeEquivalentTo(true);
sut.Equals(b1, a2).ShouldBeEquivalentTo(false);
sut.Equals(a1, b1).ShouldBeEquivalentTo(false);
}