red-black tree Clear() method

trees/redblacktree/redblacktree.go

@@ -164,7 +164,7 @@ func (tree *Tree) Keys() []interface{} {
 	return keys
 }
 
-// Returns all values in-order based on the key
+// Returns all values in-order based on the key.
 func (tree *Tree) Values() []interface{} {
 	values := make([]interface{}, tree.size)
 	for i, node := range tree.inOrder() {
@@ -173,6 +173,12 @@ func (tree *Tree) Values() []interface{} {
 	return values
 }
 
+// Removes all nodes from the tree.
+func (tree *Tree) Clear() {
+	tree.root = nil
+	tree.size = 0
+}
+
 func (tree *Tree) String() string {
 	str := "RedBlackTree\n"
 	if !tree.Empty() {

trees/redblacktree/redblacktree_test.go

@@ -141,4 +141,13 @@ func TestRedBlackTree(t *testing.T) {
 		t.Errorf("Got %v expected %v", actualValue, true)
 	}
 
+	tree.Put(1, "a")
+	tree.Put(2, "b")
+	tree.Clear()
+
+	// Test Empty()
+	if actualValue := tree.Empty(); actualValue != true {
+		t.Errorf("Got %v expected %v", actualValue, true)
+	}
+
 }