def map_citem2line(line2citem):
    """Part of `Lighthouse plugin <https://github.com/gaasedelen/lighthouse>`_

    Creates a mapping of citem indexes to lines of code
    """
    citem2line = {}
    for line, citem_l in line2citem.items():
        for citem_idx in citem_l:
            citem2line[citem_idx] = line
    return citem2line
