def build_lookup_dict_snmp_trap(list_content):
    """
    Build key/value lookup dict specifically for SNMP Traps which use "server-ip" + "version"
    :param list_content: List of dicts to derive lookup structs from
    :return: lookup dict
    """
    lookup_dict = {}

    for item in list_content:
        item_server_ip = item.get('server_ip')
        item_version = item.get('version')
        item_id = item.get('id')

        if item_server_ip and item_version and item_id is not None:
            lookup_dict["{0}+{1}".format(item_server_ip, item_version)] = item_id

    return lookup_dict