Acyclic Visitor Design Pattern The Visitor Design Pattern allow new functions to be added to existing class hierarchies without affecting those hierarchies. The Acyclic Visitor Design Pattern is saved you from implementing some unrequired methods using downcasting. The following code sample display 3 elements: Element1 , Element2 and Element3 , and two concrete visitors: Visitor12 and Visitor3 . The Acyclic Visitor Design Pattern is preventing you from implement method Visit(Element3) in Visitor12...