def get_pending_registration_ip_set(
        ip_from_dns_set, ip_from_target_group_set
):
    """
    # Get a set of IPs that are pending for registration:
    # Pending registration IPs that meet all the following conditions:
    # 1. IPs that are currently in the DNS
    # 2. Those IPs must have not been registered yet
    :param ip_from_target_group_set: a set of IPs that are currently registered with a target group
    :param ip_from_dns_set: a set of IPs that are in the DNS
    """

    pending_registration_ip_set = ip_from_dns_set - ip_from_target_group_set
    return pending_registration_ip_set