def find_all_folders(self):
        """
        compare the list of folders on disk with the list of known folders in
        our database.

        For every folder found on disk that does not exist in the database
        create an entry for it.
        """
        start_time = time.time()
        self.log.debug("find_all_folders: STARTING")
        extant_mboxes = {}
        mboxes_to_create = []
        c = self.db.cursor()
        c.execute("select name, mtime from mailboxes order by name")
        for row in c:
            name, mtime = row
            extant_mboxes[name] = mtime
        c.close()

        # The user_server's CWD is the root of our mailboxes.
        #
        for root, dirs, files in os.walk('.', followlinks=True):
            for d in dirs:
                dirname = os.path.normpath(os.path.join(root, d))
                if extant_mboxes not in dirname:
                    mboxes_to_create.append(dirname)

        # Now 'mboxes_to_create' is a list of full mailbox names that were in
        # the file system but not in the database. Instantiate these (with the
        # create flag set so that we will not get any nasty surpises about
        # missing .mh_sequence files)
        #
        for mbox_name in mboxes_to_create:
            self.log.debug("Creating mailbox %s" % mbox_name)
            self.get_mailbox(mbox_name, expiry=0)
        self.log.debug("find_all_folders: FINISHED. Took %f seconds" %
                       (time.time() - start_time))

    ##################################################################
    #
dataset/ETHPy150Open scanner/asimap/asimap/user_server.py/IMAPUserServer.find_all_folders/swapped operands of `not in`