@Test
public void testRemoveAllEdges() {

    graph.addVertex();
    graph.addVertex();
    graph.addVertex();
    graph.addEdge(0, 1, null);
    graph.addEdge(1, 0, null);
    assertEquals(2, graph.getEdgeCount());
    graph.removeAllEdges();
    assertEquals(0, graph.getEdgeCount());
}