Fixato bug e implementato alcune funzioni.

partition/ListPartition.java

@@ -7,7 +7,7 @@ import set.OrderedListSet;
 import set.Set;
 import utility.DefaultComparator;
 
-import java.security.InvalidKeyException;
+import exceptions.InvalidKeyException;
 import java.util.Iterator;
 
 /**
@@ -40,23 +40,18 @@ public class ListPartition <E> implements Partition<E> {
 
     @Override
     public Set<E> makeSet(E x) {
-        try {
+
             OrderedListSet<E> o = new OrderedListSet<E>(x, new DefaultComparator<E>());
             elementi.put(x, o);
             partizione.addLast(o);
             o.setLocation(partizione.last());
             return o;
-        }
-        catch (InvalidKeyException e){
-
-        }
-        return null;
 
     }
 
     @Override
     public Set<E> union(Set<E> A, Set<E> B) {
-        try {
+
             if (A.size() > B.size()){
                 OrderedListSet<E> AA = (OrderedListSet<E>) A;
                 OrderedListSet<E> BB = (OrderedListSet<E>) B;
@@ -82,23 +77,13 @@ public class ListPartition <E> implements Partition<E> {
 
 
             }
-        }
-        catch (InvalidKeyException e){
-
-        }
-        return null;
-
     }
 
     @Override
     public Set<E> find(E x) {
-        try {
-            return elementi.get(x);
-        }
-        catch (InvalidKeyException e){
 
-        }
-        return null;
+            return elementi.get(x);
+
     }
 
     @Override