assertThrows(
            IllegalArgumentException.class, () -> networkAsMutableNetwork.addEdge(N4, N5, E12));
    assertThat(e).hasMessageThat().contains(ERROR_REUSE_EDGE);
    e = assertThrows(IllegalArgumentException.class, () -> addEdge(N2, N1, E12));
    assertThat(e).hasMessageThat().contains(ERROR_REUSE_EDGE);
  }

  @Test
  public void addEdge_parallelEdge_notAllowed() {
    assume().that(graphIsMutable()).isTrue();

    }
    if (mapFeatures.contains(MapFeature.SUPPORTS_REMOVE)) {
      derivedFeatures.add(CollectionFeature.SUPPORTS_REMOVE);
    }
    if (mapFeatures.contains(MapFeature.REJECTS_DUPLICATES_AT_CREATION)) {
      derivedFeatures.add(CollectionFeature.REJECTS_DUPLICATES_AT_CREATION);
    }
    if (mapFeatures.contains(MapFeature.FAILS_FAST_ON_CONCURRENT_MODIFICATION)) {

                unwindTo(Arrays.asList("tr", "table", "thead", "tbody"), visitor);
            } else if (blockElements.contains(name)) {
                unwindTo("p", visitor);
            } else if (!blockContent.contains(name) && !(name.equals("a") && attributes.containsKey("name"))) {
                onInlineContent();
            }

            elementStack.addFirst(name);

            if (!switchFlg) {
                boolean contains = doc.get("content_description").toString().toLowerCase().contains(query1);
                if (!contains) {
                    switchFlg = true;
                }
            } else {
                assertTrue(doc.get("content_description").toString().toLowerCase().contains(query2), doc.toString());
            }
        }
    }

    @Test

      case FIRST_PRESENT:
        if (list.contains(key)) {
          assertEquals(list.indexOf(key), answer);
          return;
        }
        break;
      case LAST_PRESENT:
        if (list.contains(key)) {
          assertEquals(list.lastIndexOf(key), answer);
          return;
        }
        break;
      case ANY_PRESENT:
        if (list.contains(key)) {
          assertEquals(key, list.get(answer));

  /**
   * Determines whether this multiset contains the specified element.
   *
   * <p>This method refines {@link Collection#contains} to further specify that it <b>may not</b>
   * throw an exception in response to {@code element} being null or of the wrong type.
   *
   * @param element the element to check for
   * @return {@code true} if this multiset contains at least one occurrence of the element
   */
  @Override

      assertThat(network.outEdges(nodeU)).contains(edge);
      assertThat(network.incidentEdges(nodeU)).contains(edge);
      assertThat(network.predecessors(nodeV)).contains(nodeU);
      assertThat(network.adjacentNodes(nodeV)).contains(nodeU);
      assertThat(network.inEdges(nodeV)).contains(edge);
      assertThat(network.incidentEdges(nodeV)).contains(edge);

      assertThat(network.outEdges(nodeU)).contains(edge);
      assertThat(network.incidentEdges(nodeU)).contains(edge);
      assertThat(network.predecessors(nodeV)).contains(nodeU);
      assertThat(network.adjacentNodes(nodeV)).contains(nodeU);
      assertThat(network.inEdges(nodeV)).contains(edge);
      assertThat(network.incidentEdges(nodeV)).contains(edge);

      case FIRST_PRESENT:
        if (list.contains(key)) {
          assertEquals(list.indexOf(key), answer);
          return;
        }
        break;
      case LAST_PRESENT:
        if (list.contains(key)) {
          assertEquals(list.lastIndexOf(key), answer);
          return;
        }
        break;
      case ANY_PRESENT:
        if (list.contains(key)) {
          assertEquals(key, list.get(answer));

  public void testToString() {
    assertEquals("{a={1=blah}}", testTable.toString());
  }

  public void testContains() {
    assertTrue(testTable.contains('a', 1));
    assertFalse(testTable.contains('a', 2));
    assertFalse(testTable.contains('A', 1));
    assertFalse(testTable.contains('A', 2));
  }

  public void testContainsColumn() {
    assertTrue(testTable.containsColumn(1));
    assertFalse(testTable.containsColumn(2));