+ /**
+ * Creates a new sort action, given a specified action.
+ * SortAction promises to remove the given action.
+ */
+ SortAction(SortAction* sa): _action(sa){
+ }
+
+ SortAction(const SortAction& sa): _action(sa._action){
+ }
+
+ virtual const SortAction& operator=(const SortAction& sa){
+ if (this != &sa)
+ _action = sa._action;
+ return *this;
+ }
+