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    via by Unknown author

    Any worker thread runs in background, since it is not intended to loop, is not connected to a Looper.for example doInBackground(). its implementation returns will be passed to onPostExecute() which runs on the UI thread.

java.lang.ExceptionInInitializerError at at org.ros.internal.node.DefaultNode$ at org.ros.internal.node.DefaultNode$ at org.ros.concurrent.ListenerCollection$ at java.util.concurrent.ThreadPoolExecutor.runWorker( at java.util.concurrent.ThreadPoolExecutor$ at by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare() at android.os.Handler.<init>( at android.bluetooth.BluetoothAdapter$1.<init>( at android.bluetooth.BluetoothAdapter.<init>( at android.bluetooth.BluetoothAdapter.getDefaultAdapter( at at at lejos.pc.comm.NXTConnector.connectTo( at lejos.pc.comm.NXTConnector.connectTo( at at lejos.pc.comm.NXTCommandConnector.getSingletonOpen( at lejos.nxt.Motor.<clinit>( ... 7 more