public void removeAllZeros() {
    map.values().removeIf(x -> x == 0);
  }

  /**
   * Returns the sum of all values in this map.
   *
   * <p>This method is not atomic: the sum may or may not include other concurrent operations.
   */
  public long sum() {
    return map.values().stream().mapToLong(Long::longValue).sum();
  }

  @LazyInit private transient @Nullable Map<K, Long> asMap;

    Multiset<String> ms2 = HashMultiset.create(asList("b", "c"));
    assertThat(sum(ms1, ms2)).containsExactly("a", "a", "b", "b", "c");
  }

  public void testSumEmptyNonempty() {
    Multiset<String> ms1 = HashMultiset.create();
    Multiset<String> ms2 = HashMultiset.create(asList("a", "b", "a"));
    assertThat(sum(ms1, ms2)).containsExactly("a", "b", "a");
  }

  public void testSumNonemptyEmpty() {

/**
 * Optional features of classes derived from {@code List}.
 *
 * @author George van den Driessche
 */
@SuppressWarnings("rawtypes") // maybe avoidable if we rework the whole package?
@GwtCompatible
public enum ListFeature implements Feature<List> {
  SUPPORTS_SET,
  SUPPORTS_ADD_WITH_INDEX(CollectionFeature.SUPPORTS_ADD),
  SUPPORTS_REMOVE_WITH_INDEX(CollectionFeature.SUPPORTS_REMOVE),

  GENERAL_PURPOSE(

/**
 * Optional features of classes derived from {@code Multimap}.
 *
 * @author Louis Wasserman
 */
@SuppressWarnings("rawtypes") // maybe avoidable if we rework the whole package?
@GwtCompatible
public enum MultimapFeature implements Feature<Multimap> {
  VALUE_COLLECTIONS_SUPPORT_ITERATOR_REMOVE;

  private final Set<Feature<? super Multimap>> implied;

  MultimapFeature(Feature<? super Multimap>... implied) {

		modPath = parts[2]
		modDir = parts[3]
	}

	return importPath, isStd, modPath, modDir, nil
}

// adbCopyTree copies testdata, go.mod, go.sum files from subdir
// and from parent directories all the way up to the root of subdir.
// go.mod and go.sum files are needed for the go tool modules queries,
// and the testdata directories for tests.  It is common for tests to
// reach out into testdata from parent packages.

    int expectedHashCode = 0;
    for (E element : getSampleElements()) {
      expectedHashCode += (element == null) ? 0 : element.hashCode();
    }
    assertEquals(
        "A Set's hashCode() should be the sum of those of its elements.",
        expectedHashCode,
        getSet().hashCode());
  }

  @CollectionSize.Require(absent = CollectionSize.ZERO)
  @CollectionFeature.Require(ALLOWS_NULL_VALUES)

/**
 * Optional features of classes derived from {@code Set}.
 *
 * @author George van den Driessche
 */
@SuppressWarnings("rawtypes") // maybe avoidable if we rework the whole package?
@GwtCompatible
public enum SetFeature implements Feature<Set> {
  GENERAL_PURPOSE(CollectionFeature.GENERAL_PURPOSE);

  private final Set<Feature<? super Set>> implied;

  SetFeature(Feature<? super Set>... implied) {

 * can be used as keys.
 *
 * @since 4.0.0
 */
@Experimental
public interface ExtensibleEnum {

    /**
     * The {@code id} uniquely represents a value for this extensible enum.
     * This id should be used to compute the equality and hash code for the instance.
     *
     * @return the id
     */
    @Nonnull
    String id();

        assertEquals("test", testValue);
    }

    // Additional test for coverage
    public void test_additionalCoverage() {
        int a = 5;
        int b = 10;
        int sum = a + b;
        assertEquals(15, sum);

        String str = "Hello";
        assertTrue(str.startsWith("H"));
        assertTrue(str.endsWith("o"));
        assertEquals(5, str.length());
    }

        assertEquals("test", testValue);
    }

    // Additional test for coverage
    public void test_additionalCoverage() {
        int a = 5;
        int b = 10;
        int sum = a + b;
        assertEquals(15, sum);

        String str = "Hello";
        assertTrue(str.startsWith("H"));
        assertTrue(str.endsWith("o"));
        assertEquals(5, str.length());
    }