Used to assert that one value is equal to another value.
The value to test.
The value it should be equal to.
The file name that the assert failed in. Should be left as default.
The file line that the assert failed in. Should be left as default.
If values are not equal, will throw an AssertError with expected and actual values.
// Will throw an exception like "AssertError@example.d(6): <3> expected to equal <5>." int z = 3; z.shouldEqual(5);