}

  @Test
  public void removeNode_existingNodeWithSelfLoopEdge() {
    assume().that(graphIsMutable()).isTrue();
    assume().that(network.allowsSelfLoops()).isTrue();

    addNode(N1);
    addEdge(N1, N1, E11);
    assertThat(networkAsMutableNetwork.removeNode(N1)).isTrue();
    assertThat(network.nodes()).isEmpty();

   *
   * @return {@code true} if the network was modified as a result of this call
   */
  @CanIgnoreReturnValue
  boolean removeNode(N node);

  /**
   * Removes {@code edge} from this network, if it is present.
   *
   * @return {@code true} if the network was modified as a result of this call
   */
  @CanIgnoreReturnValue

  }

  @Test
  public void removeNode_existingNodeWithSelfLoopEdge() {
    assume().that(graphIsMutable()).isTrue();
    assume().that(network.allowsSelfLoops()).isTrue();

    addNode(N1);
    addEdge(N1, N1, E11);
    assertThat(networkAsMutableNetwork.removeNode(N1)).isTrue();
    assertThat(network.nodes()).isEmpty();

    for (Range<Integer> rangeToPut : RANGES) {
      for (Range<Integer> rangeToRemove : RANGES) {
        Map<Integer, Integer> model = Maps.newHashMap();
        putModel(model, rangeToPut, 1);
        removeModel(model, rangeToRemove);
        RangeMap<Integer, Integer> test = TreeRangeMap.create();
        test.put(rangeToPut, 1);
        test.remove(rangeToRemove);
        verify(model, test);
      }
    }
  }

    for (Range<Integer> rangeToPut : RANGES) {
      for (Range<Integer> rangeToRemove : RANGES) {
        Map<Integer, Integer> model = Maps.newHashMap();
        putModel(model, rangeToPut, 1);
        removeModel(model, rangeToRemove);
        RangeMap<Integer, Integer> test = TreeRangeMap.create();
        test.put(rangeToPut, 1);
        test.remove(rangeToRemove);
        verify(model, test);
      }
    }
  }