double get_amount() const { return amount_; }
void add_successor(OperationPtr op);
void remove_successor(OperationPtr op);
+ void remove_all_successors();
+ const std::set<Operation*>& get_successors() const { return successors_ ;}
void on_this_start(const std::function<void(Operation*)>& func);
void on_this_end(const std::function<void(Operation*)>& func);
int get_count() const;