You have to build the class GraphProperties (skeleton) which implements methods to calculate the eccentricity of a node, the diameter of the network, its radius and find the center of the network. import edu.princeton.cs.algs4.*; public class GraphProperties { private Graph g; public GraphProperties(Graph G) { g = G; } public int eccentricity(int v) { } public int diameter() { } public int radius() { } public int center() { } }.