//find the enemy leaders and explicit targets
    const unit_filter ufilt(vconfig(criteria));
    for (const unit &u : resources::gameboard->units()) {
        if (ufilt( u )) {
            LOG_AI_GOAL << "found explicit target unit at ... " << u.get_location() << " with value: " << value() << "\n";
            *target_list = target(u.get_location(), value(), target::TYPE::EXPLICIT);
        }
    }