How to use the mediacloud.tags.TAG_ACTION_ADD function in mediacloud

description = request.form['description']
    static = request.form['static'] if 'static' in request.form else None
    show_on_stories = request.form['showOnStories'] if 'showOnStories' in request.form else None
    show_on_media = request.form['showOnMedia'] if 'showOnMedia' in request.form else None
    source_ids = []
    if len(request.form['sources[]']) > 0:
        source_ids = request.form['sources[]'].split(',')

    formatted_name = format_name_from_label(label)
    # first create the collection
    new_collection = user_mc.createTag(TAG_SETS_ID_COLLECTIONS, formatted_name, label, description,
                                       is_static=(static == 'true'),
                                       show_on_stories=(show_on_stories == 'true'),
                                       show_on_media=(show_on_media == 'true'))
    # then go through and tag all the sources specified with the new collection id
    tags = [MediaTag(sid, tags_id=new_collection['tag']['tags_id'], action=TAG_ACTION_ADD) for sid in source_ids]
    if len(tags) > 0:
        user_mc.tagMedia(tags)
    return jsonify(new_collection['tag'])

mkey = list(m.keys())[0]
        tag_codes = tags_in_tag_set(TOOL_API_KEY, mid)
        for source in source_list:
            if mkey in source:
                metadata_tag_name = source[mkey]
                if metadata_tag_name not in ['', None]:
                    # hack until we have a better match check
                    if mkey == METADATA_PUB_COUNTRY_NAME:  # template pub_###
                        matching = [t for t in tag_codes if t['tag'] == 'pub_' + metadata_tag_name]
                    else:
                        matching = [t for t in tag_codes if t['tag'] == metadata_tag_name]

                    if matching and matching not in ['', None]:
                        metadata_tag_id = matching[0]['tags_id']
                        logger.debug('found metadata to add %s', metadata_tag_id)
                        tags.append(MediaTag(source['media_id'], tags_id=metadata_tag_id, action=TAG_ACTION_ADD))
    # now do all the tags in parallel batches so it happens quickly
    if len(tags) > 0:
        chunks = [tags[x:x + 50] for x in range(0, len(tags), 50)]  # do 50 tags in each request
        use_pool = False
        if use_pool:
            pool = Pool(processes=MEDIA_METADATA_UPDATE_POOL_SIZE)  # process updates in parallel with worker function
            pool.map(_tag_media_worker, chunks)  # blocks until they are all done
            pool.terminate()  # extra safe garbage collection
        else:
            [_tag_media_worker(job) for job in chunks]

source_to_create = {
        'name': name,
        'url': url,
        'editor_notes': editor_notes,
        'public_notes': public_notes,
        'is_monitored': monitored,
        'tags_ids': tag_ids_to_add
    }
    result = user_mc.mediaCreate([source_to_create])[0]  # need just the first entry, since we only create one
    if result['status'] != "error":
        # if it worked, update any metadata, because we need to remove the other tags in each set
        for metadata_item in valid_metadata:
            metadata_tag_id = request.form[metadata_item['form_key']] if metadata_item['form_key'] in request.form else None  # this is optional
            if metadata_tag_id:
                user_mc.tagMedia(
                    tags=[MediaTag(result['media_id'], tags_id=metadata_tag_id, action=TAG_ACTION_ADD)],
                    clear_others=True)   # make sure to clear any other values set in this metadata tag set
                tag_ids_to_add.append(metadata_tag_id)
    if result['status'] == 'new':
        # if it is a really new source, kick off a scraping job to find any RSS feeds
        user_mc.feedsScrape(result['media_id'])
    return jsonify(result)

]
    for metadata_item in valid_metadata:
        metadata_tag_id = request.form[metadata_item['form_key']] if metadata_item['form_key'] in request.form else None # this is optional
        existing_tag_ids = [t for t in source['media_source_tags'] if is_metadata_tag_set(t['tag_sets_id'])]
        # form field check
        if metadata_tag_id in [None, '', 'null', 'undefined']:
            # we want to remove it if there was one there
            if len(existing_tag_ids) > 0:
                for remove_if_empty in existing_tag_ids:
                    if metadata_item['tag_sets_id'] == remove_if_empty['tag_sets_id']:
                        tag = MediaTag(media_id, tags_id=remove_if_empty['tags_id'], action=TAG_ACTION_REMOVE)
                        user_mc.tagMedia([tag])

        elif metadata_tag_id not in existing_tag_ids:
            # need to add it and clear out the other
            tag = MediaTag(media_id, tags_id=metadata_tag_id, action=TAG_ACTION_ADD)
            user_mc.tagMedia([tag], clear_others=True)
    # result the success of the media update call - would be better to catch errors in any of these calls...
    return jsonify(result)