1. Draw class diagrams: You are asked to design classes in UML so that you can represent undirected graphs. An undirected graph consists of a set of vertices and a set of edges. Each edge connects two vertices. Your model should capture only the structure (i.e., connectivity) of such graphs. You do not need to concern with the location of vertices and the length of edges.

2. Draw object diagrams: Suppose your main function generates the follow graph with vertices v1, v2, v3, and v4, using your classes. Draw the corresponding object diagram.