As discussed previously, the second impact-related use case that we would like to address in this chapter is the one that simulates the impact of a certain change to the network on the rest of the network. It basically addresses the "what if" question: how will we be impacted if a certain change occurs in the network? What would be the optimal scenario if we were to change certain parameters in the graph structure?

The example that we will be using in this section uses a very common data structure that you may have seen in many different other use cases: a hierarchy or tree. During the course of this section, we will run through the different parts of tree structure and see what the impact of changes in the tree would be on the rest of the tree.