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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 _QueryChangeFeed(self, collection_link, resource_type, options=None, partition_key_range_id=None):
 """Queries change feed of a resource in a collection. :param str collection_link: The link to the document collection. :param str resource_type: The type of the resource. :param dict options: The request options for the request. :param str partition_key_range_id: Specifies partition key range id. :return: Query Iterable of Documents. :rtype: query_iterable.QueryIterable """

        if options is None:
            options = {}
        options['changeFeed'] = True

        resource_key_map = {'Documents' : 'docs'}

        # For now, change feed only supports Documents and Partition Key Range resouce type
        if resource_type not in resource_key_map:
            raise NotImplementedError(resource_type + " change feed query is not supported.")

        resource_key = resource_key_map[resource_type]
        path = base.GetPathFromLink(collection_link, resource_key)
        collection_id = base.GetResourceIdOrFullNameFromLink(collection_link)
        def fetch_fn(options):
            return self.__QueryFeed(path,
                                    resource_key,
                                    collection_id,
                                    lambda r: r[resource_type],
                                    lambda _, b: b,
                                    None,
                                    options,
                                    partition_key_range_id), self.last_response_headers
        return query_iterable.QueryIterable(self, None, options, fetch_fn, collection_link)