How to install ldapsearch on 16.04?

After digging around for a while under System Settings > Software & Updates I remembered once upon a time that I disabled the install updates from the following sources because I got a little annoyed with the frequent interrupting pop-ups to upgrade. I prefer to manage my upgrades manually from apt on the terminal and I didn't want it to automatically upgrade me from 16.04 to 16.10 or some other release. What I didn't realize is that these checkboxes stripped the deb package sources from /etc/apt/sources.list so it would never fetch the package updates and always report my system was up-to-date. After checking those boxes and then running apt update and upgrade I was able to successfully install ldap-utils