Android M seems to have all sorts of hidden gems and wonderful highlights which Google simply didn't have time to cover in the official Google IO 2015 keynote, or for that matter any of the sessions during the event. The main focus was on headliner features and attributes like Now On Tap and the upcoming Doze feature for preserving battery life on devices, but one doesn't need to look too far to discover all kinds of other refinements and polished edges to Google's latest version of the Android operating system. To find these personally of course you'll have to be in possession of a compatible device which can run the Android M developer preview, which is limited to the Nexus 5, Nexus 6, Nexus 9, or Nexus Player.
If you fit that bill, one feature you may not have noticed so far is a nice little enhancement to the Contacts application within Android M, which basically lets you batch select people from your contacts list to complete various tasks. If you have a number of people you want to get rid of for example, clearing them out of your contacts list in Android M is as simple as ticking the little check boxes next to each contact you want to wipe out, and then proceeding to hit the delete button. You can also use this batch select to merge contacts into a single contact which may be useful for anyone who has people in their contacts list with multiple numbers. This is assuming they're not already merged in the first place.
As you may have already suspected, the batch selection is also useful for sharing multiple contacts, so if you need to send a quick set of numbers over to someone you can do so in one fell swoop without having to drudge through every single contact individually, because let's be honest, no one has time for that kind of monotony these days. If you're already running the Android M developer preview, to check this feature out for yourself simply enter into the contacts app, long press on any contact you wish and you'll see the check boxes appear next to each contact in the list. From here you can go about merging, deleting or sharing.