def fetch(self, category=CATEGORY_MESSAGE, offset=DEFAULT_OFFSET, chats=None):
if not offset:<EOL><INDENT>offset = DEFAULT_OFFSET<EOL><DEDENT>kwargs = {"<STR_LIT>": offset, "<STR_LIT>": chats}<EOL>items = super().fetch(category, **kwargs)<EOL>return items<EOL>
Fetch the messages the bot can read from the server.

        The method retrieves, from the Telegram server, the messages
        sent with an offset equal or greater than the given.

        A list of chats, groups and channels identifiers can be set
        using the parameter `chats`. When it is set, only those
        messages sent to any of these will be returned. An empty list
        will return no messages.

        :param category: the category of items to fetch
        :param offset: obtain messages from this offset
        :param chats: list of chat names used to filter messages

        :returns: a generator of messages

        :raises ValueError: when `chats` is an empty list