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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 db_import_xml(self, url=None, force_download=False, taxids=None, silent=False):
 """Updates the CTD database 1. downloads gzipped XML 2. drops all tables in database 3. creates all tables in database 4. import XML 5. close session :param Optional[list[int]] taxids: list of NCBI taxonomy identifier :param str url: iterable of URL strings :param bool force_download: force method to download :param bool silent: """

        log.info('Update UniProt database from {}'.format(url))

        self._drop_tables()
        xml_gzipped_file_path, version_file_path = self.download(url, force_download)
        self._create_tables()
        self.import_version(version_file_path)
        self.import_xml(xml_gzipped_file_path, taxids, silent)
        self.session.close()