clickImage function

There is a function called clickLink (string $label, [integer $index = 0]) in the DrupalWebTestCase, it would be awesome to have a clickImage (string $label, [integer $x = 1], [integer $y = 1], [hash $additional = false]) function as well.

The function is defined in the simpletest framework: http://www.simpletest.org/api/SimpleTest/WebTester/SimpleBrowser.html#cl...