@Test
  public void testName() {
    Edge edge = new Edge().setTargetVertex(new Vertex());
    List<String> issues = EdgeChecker.hasIssues(edge.setName("").build());
    Assert.assertThat(issues.size(), is(0));

    issues = EdgeChecker.hasIssues(edge.setName("spaces in name").build());
    Assert.assertThat(issues.size(), is(1));
    Assert.assertThat(issues.get(0), is("Name of edge cannot have any white spaces."));
  }
  @Test
  public void testWeight() {
    Edge edge = new Edge().setTargetVertex(new Vertex());
    edge.setWeight(-1.);
    List<String> issues = EdgeChecker.hasIssues(edge.setName("").build());
    Assert.assertThat(issues.size(), is(1));
    Assert.assertThat(issues.get(0), is("The weight must be a value between 0 and 1."));

    edge.setWeight(.5);
    issues = EdgeChecker.hasIssues(edge.setName("").build());
    Assert.assertThat(issues.size(), is(0));
  }