def itemsReceived(self, event):
        """
        Fire up HTTP client to do callback
        """

        atomEntries = extractAtomEntries(event.items)
        service = event.sender
        nodeIdentifier = event.nodeIdentifier
        headers = event.headers

        # Don't notify if there are no atom entries
        if not atomEntries:
            return

        if len(atomEntries) == 1:
            contentType = MIME_ATOM_ENTRY
            payload = atomEntries[0]
        else:
            contentType = MIME_ATOM_FEED
            payload = constructFeed(service, nodeIdentifier, atomEntries,
                                    title='Received item collection')

        self.callCallbacks(service, nodeIdentifier, payload, contentType)

        if headers in 'Collection':
            for collection in headers['Collection']:
                nodeIdentifier = collection or ''
                self.callCallbacks(service, nodeIdentifier, payload,
                                   contentType)
dataset/ETHPy150Open ralphm/idavoll/idavoll/gateway.py/RemoteSubscriptionService.itemsReceived/swapped operands of `in`