public void testIsEmpty() {
    assertThat(ImmutableDoubleArray.of().isEmpty()).isTrue();
    assertThat(ImmutableDoubleArray.of(0).isEmpty()).isFalse();
    assertThat(ImmutableDoubleArray.of(0, 1, 3).isEmpty()).isFalse();
    assertThat(ImmutableDoubleArray.of(0, 1, 3).subArray(1, 1).isEmpty()).isTrue();
    assertThat(ImmutableDoubleArray.of(0, 1, 3).subArray(1, 2).isEmpty()).isFalse();
  }

  public void testGet_good() {

    Collection<V> valueCollection = map.values();
    Set<Entry<K, V>> entrySet = map.entrySet();

    assertEquals(map.size() == 0, map.isEmpty());
    assertEquals(map.size(), keySet.size());
    assertEquals(keySet.size() == 0, keySet.isEmpty());
    assertEquals(!keySet.isEmpty(), keySet.iterator().hasNext());

    int expectedKeySetHash = 0;
    for (K key : keySet) {
      V value = map.get(key);

    }

    public void setMojos(List<LifecycleMojo> mojos) {
        this.mojos = mojos;
    }

    public void set(String goals) {
        mojos = new ArrayList<>();

        if (goals != null && !goals.isEmpty()) {
            String[] mojoGoals = goals.split(",");
            mojos = Arrays.stream(mojoGoals).map(fromGoalIntoLifecycleMojo).collect(Collectors.toList());
        }
    }

        assertNotNull(ed);
        assertNotNull(ed.getExportedPackages());
        assertTrue(ed.getExportedPackages().isEmpty());
        assertNotNull(ed.getExportedArtifacts());
        assertTrue(ed.getExportedArtifacts().isEmpty());
    }

    @Test
    void testCompleteDescriptor() throws Exception {

    private static final String TEAMCITY_VERSION = "TEAMCITY_VERSION";

    @Override
    public Optional<CIInfo> detectCI() {
        String ciEnv = System.getenv(TEAMCITY_VERSION);
        if (ciEnv != null && !ciEnv.trim().isEmpty()) {
            return Optional.of(new CIInfo() {
                @Override
                public String name() {
                    return NAME;
                }
            });
        }

        } else {
            return "";
        }
    }

    @Override
    public boolean isMavenVersion(String versionRange) {
        if (Objects.requireNonNull(versionRange, "versionRange cannot be null").isEmpty()) {
            throw new IllegalArgumentException("versionRange cannot be empty");
        }

        VersionConstraint constraint;
        try {

     *         matched the requested range
     */
    @Nonnull
    default Optional<Version> getLowestVersion() {
        return getVersions().isEmpty()
                ? Optional.empty()
                : Optional.of(getVersions().get(0));
    }

    /**
     * Gets the highest version matching the requested range.
     *

                // ignored
            }
            interpolator.addValueSource(new MapBasedValueSource(System.getProperties()));

            try {
                if (fileString != null && !fileString.isEmpty()) {
                    fileString = interpolator.interpolate(fileString, "").replace("\\", "/");
                    File file = new File(fileString);
                    return file.exists();
                }

      assertTrue(Thread.holdsLock(mutex));
      return delegate.removeAll(collection);
    }

    @Override
    public boolean isEmpty() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.isEmpty();
    }

    @Override
    public boolean contains(Object object) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.contains(object);
    }

    return singletonMap(key, value).entrySet().iterator().next();
  }

  private static boolean isEmpty(Iterable<?> iterable) {
    return iterable instanceof Collection
        ? ((Collection<?>) iterable).isEmpty()
        : !iterable.iterator().hasNext();
  }

  public static void assertEmpty(Iterable<?> iterable) {
    if (!isEmpty(iterable)) {
      fail("Not true that " + iterable + " is empty");
    }
  }