@Test
  public void edgesConnecting_orderMismatch() {
    addEdge(N1, N2, E12);
    IllegalArgumentException e =
        assertThrows(
            IllegalArgumentException.class,
            () -> {
              Set<String> unused = network.edgesConnecting(EndpointPair.unordered(N1, N2));
            });
    assertThat(e).hasMessageThat().contains(ENDPOINTS_MISMATCH);
  }

  @Test

  private static final byte[] VALUES = {Byte.MIN_VALUE, -1, 0, 1, Byte.MAX_VALUE};

  public void testHashCode() {
    for (byte value : VALUES) {
      assertThat(Bytes.hashCode(value)).isEqualTo(((Byte) value).hashCode());
    }
  }

  public void testContains() {
    assertThat(Bytes.contains(EMPTY, (byte) 1)).isFalse();
    assertThat(Bytes.contains(ARRAY1, (byte) 2)).isFalse();

  }

  private static void skipHelper(long n, int expect, InputStream in) throws IOException {
    ByteStreams.skipFully(in, n);
    assertEquals(expect, in.read());
    in.close();
  }

  private static final byte[] bytes = new byte[] {0x12, 0x34, 0x56, 0x78, 0x76, 0x54, 0x32, 0x10};

  public void testNewDataInput_empty() {
    byte[] b = new byte[0];

  public void testGet_sortedSet() {
    testGetOnAbc(ImmutableSortedSet.of("b", "c", "a"));
  }

  public void testGet_emptySortedSet() {
    testGetOnEmpty(ImmutableSortedSet.<String>of());
  }

  public void testGet_iterable() {
    testGetOnAbc(ImmutableSet.of("a", "b", "c"));
  }

  public void testGet_emptyIterable() {
    testGetOnEmpty(Sets.<String>newHashSet());
  }

  }

  @Test
  public void predecessors_oneEdge() {
    putEdge(N1, N2);
    assertThat(graph.predecessors(N2)).containsExactly(N1);
    // Edge direction handled correctly
    assertThat(graph.predecessors(N1)).isEmpty();
  }

  @Test
  public void successors_oneEdge() {
    putEdge(N1, N2);
    assertThat(graph.successors(N1)).containsExactly(N2);

  }

  public void testParse_maximumWeightRepeated() {
    assertThrows(IllegalArgumentException.class, () -> parse("maximumWeight=10, maximumWeight=20"));
  }

  public void testParse_maximumSizeAndMaximumWeight() {
    assertThrows(IllegalArgumentException.class, () -> parse("maximumSize=10, maximumWeight=20"));
  }

  public void testParse_concurrencyLevel() {

  // retainAll(empty)

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testRetainAll_emptyPreviouslyEmpty() {
    expectReturnsFalse(empty);
    expectUnchanged();
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testRetainAll_emptyPreviouslyEmptyUnsupported() {
    expectReturnsFalseOrThrows(empty);
    expectUnchanged();
  }

    }

    @Override
    protected void doStart() {
      new Thread() {
        @Override
        public void run() {
          Uninterruptibles.sleepUninterruptibly(delay, TimeUnit.MILLISECONDS);
          notifyStarted();
        }
      }.start();
    }

    @Override
    protected void doStop() {
      new Thread() {
        @Override
        public void run() {

        .inOrder();
  }

  public void testStream_optionalInt() {
    assertThat(stream(OptionalInt.empty())).isEmpty();
    assertThat(stream(OptionalInt.of(5))).containsExactly(5);
  }

  public void testStream_optionalLong() {
    assertThat(stream(OptionalLong.empty())).isEmpty();
    assertThat(stream(OptionalLong.of(5L))).containsExactly(5L);
  }

  public void testStream_optionalDouble() {

public class PreconditionsTest extends TestCase {
  public void testCheckArgument_simple_success() {
    Preconditions.checkArgument(true);
  }

  public void testCheckArgument_simple_failure() {
    try {
      Preconditions.checkArgument(false);
      fail("no exception thrown");
    } catch (IllegalArgumentException expected) {
    }
  }

  public void testCheckArgument_simpleMessage_success() {