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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def notify(self, data):
 """Notify subscribers that data was received"""

        triggered_channels = []
        for channel_name, items in data.items():
            for item in items or []:
                LOG.debug('notify received: %s', item)
                try:
                    # some channels return strings rather than objects (e.g. de-registrations),
                    # normalize them here
                    item = {'value': item} if isinstance(item, six.string_types) else dict(item)
                    # inject the channel name to the data (so channels can filter on it)
                    item['channel'] = channel_name
                    triggered_channels.extend(list(self._notify_single_item(item)))
                except Exception:  # noqa
                    LOG.exception('Subscription notification failed')
        return triggered_channels