def find_in_app(self, app, path):
        """
        Find a requested static file in an app's static locations.
        """
        storage = self.storages.get(app, None)
        if storage:
            if storage.prefix:
                prefix = '%s%s' % (storage.prefix, os.sep)
                if not path.startswith(prefix):
                    return None
                path = path[len(prefix):]
            # only try to find a file if the source dir actually exists
            if storage.exists(path):
                matched_path = storage.path(path)
                if matched_path:
                    return matched_path
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.4/django/contrib/staticfiles/finders.py/AppDirectoriesFinder.find_in_app/original