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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 sync(self, query=None):
 """Fetches content from the Sync API. API Reference: https://www.contentful.com/developers/docs/references/content-delivery-api/#/reference/synchronization/initial-synchronization/query-entries :param query: (optional) Dict with API options. :return: :class:`SyncPage <contentful.sync_page.SyncPage>` object. :rtype: contentful.sync_page.SyncPage Usage: """


        if query is None:
            query = {}
        self._normalize_sync(query)

        return self._get(
            self.environment_url('/sync'),
            query
        )