fun <T> IAssertionPlant<T>.isLessOrEquals(expected: T): IAssertionPlant<T> where T : Number, T : Comparable<T>
Makes the assertion that IAssertionPlant.subject is less than or equals expected.
AssertionError - Might throw an AssertionError if the assertion made is not correct
Return
This plant to support a fluent-style API.