Looks up the walkthrough based on the given name.
        
        :param      name | <str>

def findWalkthrough(self, name):
        """
        Looks up the walkthrough based on the given name.
        
        :param      name | <str>
        """
        for walkthrough in self._walkthroughs:
            if walkthrough.name() == name:
                return walkthrough
        return None