assertEquals(rangeSet.asRanges().isEmpty(), rangeSet.isEmpty());
    assertEquals(rangeSet.asDescendingSetOfRanges().isEmpty(), rangeSet.isEmpty());
    assertEquals(!rangeSet.asRanges().iterator().hasNext(), rangeSet.isEmpty());
    assertEquals(!rangeSet.asDescendingSetOfRanges().iterator().hasNext(), rangeSet.isEmpty());

    List<Range<C>> asRanges = ImmutableList.copyOf(rangeSet.asRanges());

    }

    /**
     * Returns true if this set contains no elements.
     *
     * @return true if this set contains no elements.
     */
    @Override
    public boolean isEmpty() {
        return map.isEmpty();
    }

    /**
     * Returns true if this set contains the specified element.
     *
     * @param o
     *            element whose presence in this set is to be tested.

  public boolean contains(C value) {
    return rangeContaining(value) != null;
  }

  @Override
  public abstract @Nullable Range<C> rangeContaining(C value);

  @Override
  public boolean isEmpty() {
    return asRanges().isEmpty();
  }

  @Override
  public void add(Range<C> range) {
    throw new UnsupportedOperationException();
  }

  @Override
  public void remove(Range<C> range) {

     * Test method for
     * {@link org.codelibs.core.collection.CollectionsUtil#isEmpty(java.util.Collection)}
     * .
     */
    @Test
    public void testIsEmptyCollectionOfQ() {
        Collection<String> c = null;
        assertThat(CollectionsUtil.isEmpty(c), is(true));
        c = new ArrayList<String>();
        assertThat(CollectionsUtil.isEmpty(c), is(true));
    }

    /**
     * Test method for

     *             If the argument is <code>null</code> or an empty string.
     */
    public static void assertArgumentNotEmpty(final String argName, final String argValue) {
        if (StringUtil.isEmpty(argValue)) {
            throw new EmptyArgumentException(argName, "ECL0010", asArray(argName));
        }
    }

    /**
     * Asserts that the argument is neither <code>null</code> nor an empty string.
     *

        }
        if (!dr.getPath().isEmpty()) {
            dunc = "\\" + dr.getPath() + dunc;
        }

        if (dunc.charAt(0) != '\\') {
            log.warn("No slash at start of remaining DFS path " + dunc);
        }

        this.unc = dunc;
        if (dr.getShare() != null && !dr.getShare().isEmpty()) {
            this.share = dr.getShare();
        }

        }

        @Override
        public boolean storedInArtifactVersionDirectory() {
            return !metadata.getVersion().isEmpty();
        }

        @Override
        public boolean storedInGroupDirectory() {
            return metadata.getArtifactId().isEmpty();
        }

        @Override
        public String getGroupId() {
            return nullify(metadata.getGroupId());
        }

    assertThat(findClassesToTest(ImmutableList.of(EmptyTest.class))).isEmpty();
    assertThat(findClassesToTest(ImmutableList.of(EmptyTests.class))).isEmpty();
    assertThat(findClassesToTest(ImmutableList.of(EmptyTestCase.class))).isEmpty();
    assertThat(findClassesToTest(ImmutableList.of(EmptyTestSuite.class))).isEmpty();
  }

  public void testFindClassesToTest_noCorrespondingTestClass() {

  @CollectionSize.Require(ZERO)
  public void testIsEmpty_yes() {
    assertTrue("isEmpty() should return true", getMap().isEmpty());
  }

  @CollectionSize.Require(absent = ZERO)
  public void testIsEmpty_no() {
    assertFalse("isEmpty() should return false", getMap().isEmpty());
  }

    assertThat(requirements.getPresentFeatures()).isEmpty();
    assertThat(requirements.getAbsentFeatures()).isEmpty();
  }

  public void testBuildTesterRequirements_class_empty() throws Exception {
    @Require
    class Tester {}

    TesterRequirements requirements = buildTesterRequirements(Tester.class);

    assertThat(requirements.getPresentFeatures()).isEmpty();