import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.Multimap;

/**
 * Helper methods/assertions for use with {@code com.google.common.collect} types.
 *
 * @author Colin Decker
 */
@GwtCompatible
final class GoogleHelpers {

  private GoogleHelpers() {}

  static void assertEmpty(Multimap<?, ?> multimap) {
    if (!multimap.isEmpty()) {

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import org.jspecify.annotations.NullUnmarked;

/**
 * A byte sink for testing that has configurable behavior.
 *
 * @author Colin Decker
 */
@NullUnmarked
public class TestByteSink extends ByteSink implements TestStreamSupplier {

  private final ByteArrayOutputStream bytes = new ByteArrayOutputStream();

import java.io.ByteArrayInputStream;
import java.io.FilterReader;
import java.io.IOException;
import java.io.InputStreamReader;
import org.jspecify.annotations.NullUnmarked;

/**
 * @author Colin Decker
 */
@NullUnmarked
public class TestReader extends FilterReader {

  private final TestInputStream in;

  public TestReader(TestOption... options) throws IOException {

import java.io.ByteArrayInputStream;
import java.io.FilterReader;
import java.io.IOException;
import java.io.InputStreamReader;
import org.jspecify.annotations.NullUnmarked;

/**
 * @author Colin Decker
 */
@NullUnmarked
public class TestReader extends FilterReader {

  private final TestInputStream in;

  public TestReader(TestOption... options) throws IOException {

import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import org.jspecify.annotations.NullUnmarked;

/**
 * A char sink for testing that has configurable behavior.
 *
 * @author Colin Decker
 */
@NullUnmarked
public class TestCharSink extends CharSink implements TestStreamSupplier {

  private final TestByteSink byteSink;

  public TestCharSink(TestOption... options) {

import java.io.IOException;
import java.io.InputStream;
import java.util.Random;
import org.jspecify.annotations.NullUnmarked;

/**
 * A byte source for testing that has configurable behavior.
 *
 * @author Colin Decker
 */
@NullUnmarked
public final class TestByteSource extends ByteSource implements TestStreamSupplier {

  private final byte[] bytes;
  private final ImmutableSet<TestOption> options;

import java.io.IOException;
import java.io.InputStream;
import java.util.Random;
import org.jspecify.annotations.NullUnmarked;

/**
 * A byte source for testing that has configurable behavior.
 *
 * @author Colin Decker
 */
@NullUnmarked
public final class TestByteSource extends ByteSource implements TestStreamSupplier {

  private final byte[] bytes;
  private final ImmutableSet<TestOption> options;

import java.io.StringReader;
import java.io.Writer;
import java.util.EnumSet;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests for the default implementations of {@code CharSink} methods.
 *
 * @author Colin Decker
 */
@NullUnmarked
public class CharSinkTest extends IoTestCase {

  private static final String STRING = ASCII + I18N;

  private TestCharSink sink;

  @Override
  public void setUp() {

import org.jspecify.annotations.Nullable;

/**
 * Abstract {@link Hasher} that handles converting primitives to bytes using a scratch {@code
 * ByteBuffer} and streams all bytes to a sink to compute the hash.
 *
 * @author Colin Decker
 */
abstract class AbstractByteHasher extends AbstractHasher {
  private @Nullable ByteBuffer scratch;

  /** Updates this hasher with the given byte. */
  protected abstract void update(byte b);

import java.lang.invoke.MethodType;
import java.nio.ByteBuffer;
import java.util.zip.Checksum;
import org.jspecify.annotations.Nullable;

/**
 * {@link HashFunction} adapter for {@link Checksum} instances.
 *
 * @author Colin Decker
 */
@Immutable
final class ChecksumHashFunction extends AbstractHashFunction implements Serializable {
  private final ImmutableSupplier<? extends Checksum> checksumSupplier;
  private final int bits;