Sample app crashes with unhandled exception during emulator shutdown

[qwwdfsad]

E/AndroidRuntime: FATAL EXCEPTION: camera
                  Process: com.beepiz.cameracoroutines.sample, PID: 4679
                  kotlinx.coroutines.experimental.channels.ClosedSendChannelException: Channel was closed
                      at kotlinx.coroutines.experimental.channels.ConflatedBroadcastChannel$Closed.getSendException(ConflatedBroadcastChannel.kt:61)
                      at kotlinx.coroutines.experimental.channels.ConflatedBroadcastChannel.offer(ConflatedBroadcastChannel.kt:222)
                      at com.beepiz.cameracoroutines.CamCaptureSession.stateCallback(CamCaptureSession.kt:127)
                      at com.beepiz.cameracoroutines.CamCaptureSession.access$stateCallback(CamCaptureSession.kt:32)
                      at com.beepiz.cameracoroutines.CamCaptureSession$sessionStateCallback$1.onReady(CamCaptureSession.kt:67)
                      at android.hardware.camera2.impl.CallbackProxies$SessionStateCallbackProxy.lambda$onReady$2(CallbackProxies.java:74)
                      at android.hardware.camera2.impl.-$$Lambda$CallbackProxies$SessionStateCallbackProxy$Hoz-iT1tD_pl7sCGu4flyo-xB90.run(Unknown Source:4)
                      at android.os.Handler.handleCallback(Handler.java:873)
                      at android.os.Handler.dispatchMessage(Handler.java:99)
                      at android.os.Looper.loop(Looper.java:193)
                      at android.os.HandlerThread.run(HandlerThread.java:65)