public Iterator<Counter> iterateGroup(String grpName){
  Collection<Counter> grpCounters=new ArrayList<>();
  for (  HadoopLongCounter counter : cntrs.values()) {
    if (grpName.equals(counter.group()))     grpCounters.add(new HadoopV2Counter(counter));
  }
  return grpCounters.iterator();
}

public Iterator < Counter > iterateGroup ( String grpName ) { Collection < Counter > grpCounters = new ArrayList < > ( ) ; for ( HadoopLongCounter counter : cntrs . values ( ) ) { if ( grpName . equals ( counter . group ( ) ) ) grpCounters . add ( new HadoopV2Counter ( counter ) ) ; } return grpCounters . iterator ( ) ; }
returns counters iterator for specified group .
