def METHOD_NAME(cls, url):
    """ Get the perceval params given a mattermost URL
    Mattermost URLs can be passed in two formats:
    - Legacy, which looks like <base_url> <channel_id>
    - Standard, which is just the URL for a specific channel.
    An example Legacy "URL" looks like `https://my.mattermost.host/
    993bte1an3dyjmqdgxsr8jr5kh`
    An example Standard URL looks like
    `https://my.mattermost.host/my_team_name/channels/my_channel_name`
    """
    params = []
    # Match the provided URL against the validator/parser regex
    data = cls.URL_REGEX.match(url.lower())
    # If there was no match, the URL was formatted wrong
    if data is None:
        raise RuntimeError(f"Couldn't parse mattermost URL ({url}), unknown format\n"
                           "URLs must be either a url like "
                           "'https://my.mattermost.host/my_team_name/channels/my_channel_name' "
                           "or just a base URL and a channel ID, such as "
                           "'https://my.mattermost.host/ 993bte1an3dyjmqdgxsr8jr5kh'")
    # The `base` group should be matched for both URLs, and is the 1st parameter
    url = data.group('base')
    params.append(url)
    # Extract the other groups
    team = data.group('team')
    channel = data.group('channel')
    channel_id = data.group('channel_id')
    # Check if this is a Standard URL by the presence of the `team` group
    if team is not None:
        params.append(channel)
        params.append(team)
    else:
        params.append(channel_id)
    return params