question: public void cancel ( ) { if ( mUploadOperation == null ) { if ( mUploadStarted . get ( ) ) { Log_OC . d ( TAG , "Cancelling upload during upload preparations." ) ; mCancellationRequested . set ( true ) ; } else { Log_OC . e ( TAG , "No upload in progress. This should not happen." ) ; } } else { Log_OC . d ( TAG , "Cancelling upload during actual upload operation." ) ; mUploadOperation . cancel ( ) ; } }
target:  Allows to cancel the actual upload operation. If actual upload operating is in progress it is cancelled, if upload preparation is being performed upload will not take place.