'Get episode ids from the show id and the season.
:param int show_id: show id.
:param int season: season of the episode.
:return: episode ids per episode number.
:rtype: dict'

@region.cache_on_arguments(expiration_time=EPISODE_EXPIRATION_TIME)
def get_episode_ids(self, show_id, season):

    logger.info('Getting    the    page    of    show    id    %d,    season    %d', show_id, season)
    r = self.session.get((self.server_url + ('tvshow-%d-%d.html' % (show_id, season))), timeout=10)
    soup = ParserBeautifulSoup(r.content, ['lxml', 'html.parser'])
    episode_ids = {}
    for row in soup.select('table#table5    tr'):
        if (not row('a', href=episode_id_re)):
            continue
        cells = row('td')
        episode = int(cells[0].text.split('x')[1])
        episode_id = int(cells[1].a['href'][8:(-5)])
        episode_ids[episode] = episode_id
    if episode_ids:
        logger.debug('Found    episode    ids    %r', episode_ids)
    else:
        logger.warning('No    episode    ids    found')
    return episode_ids
