iPad Modal window and hiding keyboard on blur

So, I am working on a project where I use a modal window (MODAL_PRESENTATION_FORMSHEET) on the iPad in which the user can see the settings for the app. The problem is that when they first enter a textfield and the keyboard shows up, running textfield.blur() won't hide the keyboard as it would do anywhere else in the app.

Now, I found the issue in the tracker here: https://jira.appcelerator.org/browse/TIMOB-3109?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel - and they seem to have concluded that this is what was intended by Apple.

It just so happens that there does seem to be a solution, ( which I read about here: http://stackoverflow.com/questions/3372333/ipad-keyboard-will-not-dismiss-if-modal-view-controller-presentation-style-is-ui ). My question is; where (in which of the files in the SDK) should I insert this code:

- (BOOL)disablesAutomaticKeyboardDismissal {
    return NO;
}