}
    }

    try {
      Range<C> span = rangeSet.span();
      assertEquals(expectedSpan, span);
    } catch (NoSuchElementException e) {
      assertThat(expectedSpan).isNull();
    }

    // test that asDescendingSetOfRanges is the reverse of asRanges
    assertEquals(Lists.reverse(asRanges), ImmutableList.copyOf(rangeSet.asDescendingSetOfRanges()));
  }

    assertThat(INSTANCE.toString()).isEqualTo("{}");
  }

  public void testSize() {
    assertEquals(0, INSTANCE.size());
  }

  public void testGet() {
    assertThat(INSTANCE.get('a', 1)).isNull();
  }

  public void testIsEmpty() {
    assertTrue(INSTANCE.isEmpty());
  }

  public void testCellSet() {
    assertEquals(ImmutableSet.of(), INSTANCE.cellSet());
  }

  public void testColumn() {

      assertThat(root.getParent()).isNull();
      assertThat(root.toRealPath().getParent()).isNull();
      MoreFiles.createParentDirectories(root); // test that there's no exception
    }
  }

  public void testCreateParentDirectories_relativePath() throws IOException {
    Path path = FS.getPath("nonexistent.file");
    assertThat(path.getParent()).isNull();

    assertThat(TypeToken.of(Object.class).getComponentType()).isNull();
    assertThat(TypeToken.of(void.class).getComponentType()).isNull();
  }

  public <T> void testGetComponentType_genericArrayClasses() {
    assertThat(TypeToken.of(new TypeCapture<T>() {}.capture()).getComponentType()).isNull();
    assertEquals(
        TypeToken.of(new TypeCapture<T>() {}.capture()),

        ImmutableSortedSet.copyOf(new String[] {"e", "e", "f", "b", "i", "d", "c", "k"});
    assertThat(set.floor("a")).isNull();
  }

  public void testCeiling_emptySet() {
    ImmutableSortedSet<String> set = ImmutableSortedSet.copyOf(new String[] {});
    assertThat(set.ceiling("f")).isNull();
  }

  public void testCeiling_elementPresent() {
    ImmutableSortedSet<String> set =

    // True if getValue never returns null.
    private boolean isFull() {
      return size == keyToIndex().size();
    }

    K getKey(int index) {
      return keyToIndex().keySet().asList().get(index);
    }

    abstract @Nullable V getValue(int keyIndex);

    @Override
    ImmutableSet<K> createKeySet() {
      return isFull() ? keyToIndex().keySet() : super.createKeySet();
    }

      assertFalse(name, domain.hasPublicSuffix());
      assertFalse(name, domain.isUnderPublicSuffix());
      assertFalse(name, domain.isTopPrivateDomain());
      assertThat(domain.publicSuffix()).isNull();
    }

    for (String name : NON_PS) {
      InternetDomainName domain = InternetDomainName.from(name);
      assertFalse(name, domain.isPublicSuffix());
      assertTrue(name, domain.hasPublicSuffix());

	}
}

func coalesce(args []*Value) (res *Value, err error) {
	for _, arg := range args {
		if arg.IsNull() {
			continue
		}
		return arg, nil
	}
	return FromNull(), nil
}

func nullif(v1, v2 *Value) (res *Value, err error) {
	// Handle Null cases
	if v1.IsNull() || v2.IsNull() {
		return v1, nil
	}

	err = inferTypesForCmp(v1, v2)
	if err != nil {
		return nil, err
	}

    String string = source.read();
    assertExpectedString(string);
  }

  public void testReadFirstLine() throws IOException {
    if (expectedLines.isEmpty()) {
      assertThat(source.readFirstLine()).isNull();
    } else {
      assertThat(source.readFirstLine()).isEqualTo(expectedLines.get(0));
    }
  }

  public void testReadLines_toList() throws IOException {
    assertExpectedLines(source.readLines());

import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.isNull;
import static org.mockito.ArgumentMatchers.same;
import static org.mockito.Mockito.doAnswer;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.never;
import static org.mockito.Mockito.times;