code: def update(connection=None, urls=None, force_download=False, taxids=None, silent=False):
      
      if isinstance(taxids, int):
          taxids = (taxids,)
      db = DbManager(connection)
      db.db_import_xml(urls, force_download, taxids, silent)
      db.session.close()
docs: Updates CTD database
  
      :param urls: list of urls to download
      :type urls: iterable
      :param connection: custom database connection string
      :type connection: str
      :param force_download: force method to download
      :type force_download: bool
      :param int,list,tuple taxids: int or iterable of NCBI taxonomy identifiers (default is None = load all)