void restore(){
  System.arraycopy(counterSave,0,counter,0,blockSize);
  System.arraycopy(encryptedCounterSave,0,encryptedCounter,0,blockSize);
  used=usedSave;
}

void restore ( ) { System . arraycopy ( counterSave , 0 , counter , 0 , blockSize ) ; System . arraycopy ( encryptedCounterSave , 0 , encryptedCounter , 0 , blockSize ) ; used = usedSave ; }
restores the content of this cipher to the previous saved one .
