Write a method for `Integer`

instances named
`celsiusToFahrenheit`

that, when sent to a number representing temperature in Celsius
answers twice that number plus 30.

Next, amend your `celsiusToFahrenheit`

method such that it displays
“Performing an approximate temperature conversion” every time that it is
entered.

Next, improve your `celsiusToFahrenheit`

method by having it add 40 to
the argument, multiply by *9/5*, and subtract 40. Be sure that your
method answers with an integer.

Finally, change your `celsiusToFahrenheit`

method such that the receiver is in
Celsius degrees relative to absolute zero and the result answered is in
Fahrenheit degrees relative to absolute zero. Absolute zero is *-273*
degrees Celsius.

For each change, comment on the corresponding benefit provided by procedure abstraction.