def check_for_duplicate_ids(id_map) -> bool:
    """
    Checks for duplicate ids in the map
    :param id_map: The id_map generated by build_id_dict()
    :return: True if duplicate non-null id's exist, false otherwise
    """
    used_ids = set()
    for sheet in id_map.keys():
        for row in id_map[sheet].keys():
            current_id = id_map[sheet][row]
            if current_id is not None and current_id in used_ids:
                return True
            used_ids.add(current_id)
    return False