➜ pmset -g assertions
2017-01-05 17:56:57 +0300
Assertion status system-wide:
   BackgroundTask                 0
   ApplePushServiceTask           0
   UserIsActive                   1
   PreventUserIdleDisplaySleep    0
   PreventSystemSleep             0
   ExternalMedia                  0
   PreventUserIdleSystemSleep     0
   NetworkClientActive            0
Listed by owning process:
   pid 704(hidd): [0x00003e370009012f] 00:53:42 UserIsActive named: "com.apple.iohideventsystem.queue.tickle"
	Timeout will fire in 112 secs Action=TimeoutActionRelease
No kernel assertions.
Idle sleep preventers: IODisplayWrangler