- fix treeset iterator Last() function

sets/treeset/iterator.go

@@ -85,5 +85,5 @@ func (iterator *Iterator) First() bool {
 // Modifies the state of the iterator.
 func (iterator *Iterator) Last() bool {
 	iterator.End()
-	return iterator.iterator.Last()
+	return iterator.Prev()
 }

sets/treeset/treeset_test.go

@@ -265,10 +265,10 @@ func TestSetIteratorPrev(t *testing.T) {
 }
 
 func TestSetIteratorBegin(t *testing.T) {
-	m := NewWithStringComparator()
-	it := m.Iterator()
+	set := NewWithStringComparator()
+	it := set.Iterator()
 	it.Begin()
-	m.Add("a", "b", "c")
+	set.Add("a", "b", "c")
 	for it.Next() {
 	}
 	it.Begin()
@@ -322,8 +322,8 @@ func TestSetIteratorLast(t *testing.T) {
 	if actualValue, expectedValue := it.Last(), true; actualValue != expectedValue {
 		t.Errorf("Got %v expected %v", actualValue, expectedValue)
 	}
-	if index, value := it.Index(), it.Value(); index != 3 || value != "c" {
-		t.Errorf("Got %v,%v expected %v,%v", index, value, 3, "c")
+	if index, value := it.Index(), it.Value(); index != 2 || value != "c" {
+		t.Errorf("Got %v,%v expected %v,%v", index, value, 2, "c")
 	}
 }