public E peekBackwards(){
  int prevPos=(pos + size - 1) % size;
  if (prevPos >= data.size() || pos == start) {
    return null;
  }
  return data.get(prevPos);
}

public E peekBackwards ( ) { int prevPos = ( pos + size - 1 ) % size ; if ( prevPos >= data . size ( ) || pos == start ) { return null ; } return data . get ( prevPos ) ; }
return the previous element ( if present ) , without moving the position in the history .
