'When a anonymous user create a mail.channel, the operator is not notify (to avoid massive polling when
clicking on livechat button). So when the anonymous person is sending its FIRST message, the channel header
should be added to the notification, since the user cannot be listining to the channel.'

@api.multi
def _channel_message_notifications(self, message):

    notifications = super(MailChannel, self)._channel_message_notifications(message)
    message_values_dict = (notifications[0][1] if len(notifications) else dict(message.message_format()[0]))
    for channel in self:
        if (channel.channel_type == 'livechat'):
            notifications.append([channel.uuid, message_values_dict])
    if (not message.author_id):
        unpinned_channel_partner = self.mapped('channel_last_seen_partner_ids').filtered((lambda cp: (not cp.is_pinned)))
        if unpinned_channel_partner:
            unpinned_channel_partner.write({'is_pinned': True})
            notifications = (self._channel_channel_notifications(unpinned_channel_partner.mapped('partner_id').ids) + notifications)
    return notifications
