Feature Request: Select block of code/method, hit key, shows example execution

Here's a feature that I think could offer a major advantage for IntelliJ - as important as code navigation and refactoring.

Imagine I have some code:

public String doSomething(String s) {
  return s + " hello " + s.trim();
}

And some other code:

// bunch of stuff
doSomething(someString)

Now, currently, with the cursor on doSomething, I can hit ctrl-shift-i to show the underlying code.

What  would be awesome is if I could hit another keystroke (or maybe the  same) and it would popup a table showing some example inputs and  results.

Eg

Potential issues:
-  coming up with list of inputs - really not that hard - for Strings, the  list above would be enough to cater for a lot of cases - alternatively,  it could be interactive, have an editable textbox for each input, run  the code and update the results on the fly as you type, like the Regex  plugin
- complex parameters - ie compound objects - that's ok,  just don't support that use case initially, just handling Strings and  primitives would be great initially

If not a core part of the product, maybe someone keen could hack up a plugin to demonstrate the concept.

BTW I originally posted this in the EAP discussion group but then looked at the list of recent messages and it appears very dead... - so posting it here instead.