}

  public void testContentEquals() throws IOException {
    assertTrue(source.contentEquals(source));
    assertTrue(source.wasStreamOpened() && source.wasStreamClosed());

    ByteSource equalSource = new TestByteSource(bytes);
    assertTrue(source.contentEquals(equalSource));
    assertTrue(new TestByteSource(bytes).contentEquals(source));

      for (int j = 0; j < i; j++) {
        Map<Integer, @Nullable Integer> source = new TreeMap<>();
        for (int k = 0; k < i; k++) {
          source.put(k, k);
        }
        source.put(j, null);
        try {
          ImmutableSortedMap.copyOf((Map<Integer, Integer>) source);
          fail("Expected NullPointerException in copyOf(" + source + ")");
        } catch (NullPointerException expected) {
        }
      }

   * @since 6.0 (source-compatible since 2.0)
   */
  public static <E> ImmutableMultiset<E> of(E element) {
    return copyFromElements(element);
  }

  /**
   * Returns an immutable multiset containing the given elements, in order.
   *
   * @throws NullPointerException if any element is null
   * @since 6.0 (source-compatible since 2.0)
   */

      } else {
        throw new UnknownElementException(nextElements, e);
      }
    }

    private E transferElement(Stack<E> source, Stack<E> destination) {
      if (source.isEmpty()) {
        throw PermittedMetaException.NSEE;
      }

      destination.push(source.pop());
      stackWithLastReturnedElementAtTop = destination;
      return destination.peek();
    }

  }

  public void testContentEquals() throws IOException {
    assertTrue(source.contentEquals(source));
    assertTrue(source.wasStreamOpened() && source.wasStreamClosed());

    ByteSource equalSource = new TestByteSource(bytes);
    assertTrue(source.contentEquals(equalSource));
    assertTrue(new TestByteSource(bytes).contentEquals(source));

    assertEquals(STRING.length(), source.copyTo(sink));
    assertTrue(source.wasStreamOpened() && source.wasStreamClosed());
    assertTrue(sink.wasStreamOpened() && sink.wasStreamClosed());

    assertEquals(STRING, sink.getString());
  }

  public void testRead_toString() throws IOException {
    assertEquals(STRING, source.read());
    assertTrue(source.wasStreamOpened() && source.wasStreamClosed());
  }

  public void testPartition_badSize() {
    List<Integer> source = Collections.singletonList(1);
    try {
      Lists.partition(source, 0);
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  public void testPartition_empty() {
    List<Integer> source = Collections.emptyList();
    List<List<Integer>> partitions = Lists.partition(source, 1);
    assertTrue(partitions.isEmpty());

   *
   * <p>After {@code remove} is invoked on a generated iterator, the removed element will no longer
   * appear in either that iterator or any other iterator created from the same source iterable.
   * That is, this method behaves exactly as {@code Iterables.cycle(Lists.newArrayList(elements))}.
   * The iterator's {@code hasNext} method returns {@code true} until all of the original elements

      } else {
        throw new UnknownElementException(nextElements, e);
      }
    }

    private E transferElement(Stack<E> source, Stack<E> destination) {
      if (source.isEmpty()) {
        throw PermittedMetaException.NSEE;
      }

      destination.push(source.pop());
      stackWithLastReturnedElementAtTop = destination;
      return destination.peek();
    }

  }

  @Test
  public void source_oneEdge() {
    addEdge(N1, N2, E12);
    assertThat(network.incidentNodes(E12).source()).isEqualTo(N1);
  }

  @Test
  public void source_edgeNotInGraph() {
    IllegalArgumentException e =
        assertThrows(
            IllegalArgumentException.class,
            () -> network.incidentNodes(EDGE_NOT_IN_GRAPH).source());
    assertEdgeNotInGraphErrorMessage(e);
  }