private void capacity(int minCap){
  counters.ensureCapacity(minCap);
  while (counters.size() < minCap)   counters.add(0);
}

private void capacity ( int minCap ) { counters . ensureCapacity ( minCap ) ; while ( counters . size ( ) < minCap ) counters . add ( 0 ) ; }
ensure counters capacity and initial state .
