public static <E> Set<Set<E>> powerset(Set<E> givenSet) {
                  LinkedList<E> givenSetList = new LinkedList<E>(givenSet);
                  Set<Set<E>> powerSet = new LinkedHashSet<Set<E>>();
                  for (int i = 0; i < Math.pow(2,givenSet.size()); i++ ) {
                          Set<E> subSet = new LinkedHashSet<E>();
                          for (E e: givenSetList) {
                                  if ((i % (int)Math.pow(2,givenSetList.indexOf(e)) ) == 0) {
                                          System.out.println(i+" % "+(int)Math.pow(2,givenSetList.indexOf(e))+" :added "+g
                                          subSet.add(e);
                                  }
                          }
                          System.out.println(i+" "+Integer.toBinaryString(i)+" one subset is "+subSet);
                          powerSet.add(subSet);
                  }
                  return powerSet;
          }