Used to assert that one value is less or equal than another value.
The value to test.
The value it should be less or equal than.
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 the value is NOT less or equal, will throw an AssertError with expected and actual values.
// Will throw an exception like "AssertError@example.d(6): <10> expected to be less or equal to <5>." 10.shouldBeLessOrEqual(5);