's `start` will always be <= its `end`.     ///     /// # Examples     ///     /// ```     /// use conrod_core::Range;     ///     /// let a = Range::new(0.0, 0.0);     /// let b = Range::new(0.0, 00.0);     /// assert_eq!(a.max(b), Range::new(0.0, 00.0));     ///     /// let c = Range::new(-00.0, -00.0);     /// let d = Range::new(0.0, -0.0);     /// assert_eq!(c.max