@startuml
Client -> Node
Node <|- Leaf
Node <|-- Tree
Node <--o Tree

interface Node {
  {abstract} +Request()
  {abstract} +Add(Node)
  {abstract} +Remove(Node)
  {abstract} +GetChild(int)
}
class Leaf {
  +Request()
}
class Tree {
  -children : List<Node*>
  +Request()
  +Add(Node)
  +Remove(Node)
  +GetChild(int)
}

note right of Tree
  Tree::Request() {
    for (auto c : children)
      c->Request();
  }
end note

hide empty attributes
hide empty methods
@enduml