update

src/main/java/rocks/zipcode/io/quiz4/generics/GenericUtils.java

@@ -8,11 +8,12 @@ import java.util.TreeSet;
  * @author leon on 11/12/2018.
  */
 public class GenericUtils {
-    public static <_ extends Comparable> Iterable<Iterable<_>> powerSet(Set<_> originalSet) {
+    public static <_ extends Comparable> Iterable<? extends Iterable<_>> powerSet(Set<_> originalSet) {
         return null;
     }
 
-    public static <_ extends Comparable> Iterable<Iterable<_>> powerSet(_... originalSet) {
+    public static <_ extends Comparable> Iterable<? extends Iterable<_>> powerSet(_... originalSet) {
         return powerSet(new TreeSet<>(Arrays.asList(originalSet)));
     }
 }
+

src/test/java/rocks/zipcode/io/quiz4/objectorientation/palindromeobject/PalindromeObjectIsPalindromeTestNegative.java

@@ -25,6 +25,6 @@ public class PalindromeObjectIsPalindromeTestNegative {
     }
 
     public void test(String input) {
-        Assert.assertTrue(new PalindromeObject(input).isPalindrome());
+        Assert.assertFalse(new PalindromeObject(input).isPalindrome());
     }
 }

src/test/java/rocks/zipcode/io/quiz4/utils/MyTestClass.java

@@ -1,54 +0,0 @@
-package rocks.zipcode.io.quiz4.utils;
-
-import rocks.zipcode.io.quiz4.collections.ComparableTreeSet;
-
-import java.util.*;
-
-/**
- * @author leon on 18/12/2018.
- */
-public class MyTestClass {
-
-    public static <E> Set<Set<E>> findPowerSet(Set<E> set) {
-        Set<Set<E>> ret = new TreeSet<>();
-        ret.add(set);
-        if (set.isEmpty()) {
-            return ret;
-        }
-        Iterator<E> it = set.iterator();
-        while (it.hasNext()) {
-            Set<E> tmp = (Set)new ComparableTreeSet(set);   //create a copy of current set
-            tmp.remove(it.next());              //remove current element from copy set
-            ret.add(tmp);                       //add the remaining set to result
-            ret.addAll(findPowerSet(tmp));      //recursively find subsets of copy set
-        }
-        return ret;
-    }
-
-    public static void main(String[] args) {
-        Set<Character> set = (Set)new ComparableTreeSet<Character>();
-        set.add('x');
-        set.add('y');
-        set.add('z');
-        set.add('t');
-        System.out.println("Input set");
-        printSet(set);
-        System.out.println("\nsub sets");
-        findPowerSet(set).stream().forEach(MyTestClass::printSet);
-    }
-
-
-    public static <E> void printSet(E... val) {
-        printSet(new TreeSet<>(Arrays.asList(val)));
-    }
-
-    public static <E> void printSet(Set<E> set) {
-        StringBuilder sb = new StringBuilder(set.size() == 0 ? "{}\n" : "{");
-        Iterator<E> it = set.iterator();
-        while (it.hasNext()) {
-            sb.append(it.next().toString())
-                    .append(it.hasNext() ? ", " : "}\n");
-        }
-        System.out.print(sb.toString());
-    }
-}