I can show this by an example:

## Given this code:
blah = run(1,2,3,(somethingReallyComplex(x,y,z)))

## And I introduce this part of it: somethingReallyComplex(x,y,z) with the name "introducedVariable"
## I get this:

blah = run(1,2,3,(var introducedVariable = somethingReallyComplex(x,y,z);))

## The "var" statement is actually a syntax error in CoffeeScript and the ";" within the parens is also invalid