2017-08-20 12:10:43 +1000
Assertion status system-wide:
   BackgroundTask                 0
   ApplePushServiceTask           0
   UserIsActive                   1
   PreventUserIdleDisplaySleep    0
   PreventSystemSleep             0
   ExternalMedia                  1
   PreventUserIdleSystemSleep     1
   NetworkClientActive            0
Listed by owning process:
   pid 59(powerd): [0x0000004100088000] 39:29:46 ExternalMedia named: "com.apple.powermanagement.externalmediamounted"
   pid 251(mds_stores): [0x0001272e000ba305] 00:04:18 BackgroundTask named: "com.apple.metadata.mds_stores.power"
   pid 114(hidd): [0x000100dd0009997a] 03:36:53 UserIsActive named: "com.apple.iohideventsystem.queue.tickle.4294967962.3"
    Timeout will fire in 110 secs Action=TimeoutActionRelease
   pid 72(mds): [0x000126ae000ba2d1] 00:06:26 BackgroundTask named: "com.apple.metadata.mds.power"
   pid 57(configd): [0x000122640007a186] 00:24:44 DenySystemSleep named: "InternetSharingPreferencePlugin"
   pid 193(coreaudiod): [0x000122260001889a] 00:25:46 PreventUserIdleSystemSleep named: "com.apple.audio.AppleHDAEngineOutput:1B,0,1,1:0.context.preventuseridlesleep"
    Created for PID: 438.
Kernel Assertions: 0x4=USB
   id=503  level=255 0x4=USB mod=1/1/70, 10:00 am description=com.apple.usb.externaldevice.14500000 owner=BUP Slim Mac SL
Idle sleep preventers: IODisplayWrangler