def METHOD_NAME(file_name):
    """
    Loads tag groups from a text file.
    A tag group is defined by specifying a space separated list of tags within
    a single line. Lines that are empty or start with '#' are ignored.
    """
    tag_groups = []
    # Load tag group specifications
    with open(file_name, "r") as fp:
        for line in fp:
            line = line.strip()
            if len(line) == 0 or line.startswith("#"):
                continue
            group = set(line.split())
            if len(group):
                tag_groups.append(group)
    # Check if all tag groups are exclusive
    for tag_group_a, tag_group_b in itertools.combinations(tag_groups, 2):
        tags = tag_group_a & tag_group_b
        if len(tags):
            raise RuntimeError(
                "Tag(s) {} are present in multiple groups".format(
                    " ".join(tags)))
    return tag_groups