title: Main Thread Checker: UI API called on a background thread: -[UIApplication delegate]
body: <p>Xcode 9 seems to be reporting a lot of Main thread calls to UIApplication properties. Even though the UI is not being updated this is particularly cumbersome due to the extension of logs it produces a default environment.</p>
  
  <pre><code>4   TestApp                             0x0000000101c262e0 __39-[ViewController viewDidLoad]_block_invoke + 196
  5   libdispatch.dylib                   0x0000000102279654 _dispatch_call_block_and_release + 24
  6   libdispatch.dylib                   0x0000000102279614 _dispatch_client_callout + 16
  7   libdispatch.dylib                   0x0000000102289008 _dispatch_queue_serial_drain + 716
  8   libdispatch.dylib                   0x000000010227ce58 _dispatch_queue_invoke + 340
  9   libdispatch.dylib                   0x000000010228a1c4 _dispatch_root_queue_drain_deferred_wlh + 412
  10  libdispatch.dylib                   0x00000001022917fc _dispatch_workloop_worker_thread + 868
  11  libsystem_pthread.dylib             0x00000001ac6771e8 _pthread_wqthread + 924
  12  libsystem_pthread.dylib             0x00000001ac676e40 start_wqthread + 4
  </code></pre>