 /// Next, the observations in Celsius are converted to Fahrenheit:
 ///
 ///     let tempsFahrenheit = tempsCelsius.map { $0 * 1.8 + 32 }
-///     // tempsFahrenheit == [70.7, 66.65, 80.6, nan, 82.85, nan, 73.4]
+///     print(tempsFahrenheit)
+///     // Prints "[70.7, 66.65, 80.6, nan, 82.85, nan, 73.4]"
 ///
 /// The NaN values in the `tempsCelsius` array are propagated through the
 /// conversion and remain NaN in `tempsFahrenheit`.

///
///     let temperatureData = ["21.5", "19.25", "27", "no data", "28.25", "no data", "23"]
///     let tempsCelsius = temperatureData.map { Double($0) ?? .nan }
///     // tempsCelsius == [21.5, 19.25, 27, nan, 28.25, nan, 23.0]
///
/// Note that some elements in the `temperatureData ` array are not valid
/// numbers. When these invalid strings are parsed by the `Double` failable

  ///
  ///     var numbers = [2.5, 21.25, 3.0, .nan, -9.5]
  ///     numbers.sort { !$1.isTotallyOrdered(belowOrEqualTo: $0) }
  ///     print(numbers)
  ///     // Prints "[-9.5, 2.5, 3.0, 21.25, nan]"
  ///
  /// The `isTotallyOrdered(belowOrEqualTo:)` method implements the total order
  /// relation as defined by the [IEEE 754 specification][spec].
