public void sort(Comparator<OperatorDescription> comparator){
  Collections.sort(operators,comparator);
  for (  GroupTree child : children.values()) {
    child.sort(comparator);
  }
}

public void sort ( Comparator < OperatorDescription > comparator ) { Collections . sort ( operators , comparator ) ; for ( GroupTree child : children . values ( ) ) { child . sort ( comparator ) ; } }
this method will sort this grouptree according to the given comparator .
