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 static com.google.common.base.Charsets.UTF_8;
import static com.google.common.base.Preconditions.checkNotNull;

import java.io.FilterWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;

/** @author Colin Decker */
public class TestWriter extends FilterWriter {

  private final TestOutputStream out;

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

import com.google.common.collect.ImmutableSet;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;

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

  private final ByteArrayOutputStream bytes = new ByteArrayOutputStream();
  private final ImmutableSet<TestOption> options;

import static com.google.common.base.Charsets.UTF_8;
import static com.google.common.base.Preconditions.checkNotNull;

import java.io.FilterWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;

/** @author Colin Decker */
public class TestWriter extends FilterWriter {

  private final TestOutputStream out;

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

import java.io.FilterWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;

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

  private final TestByteSink byteSink;

  public TestCharSink(TestOption... options) {

import com.google.errorprone.annotations.Immutable;
import java.io.Serializable;
import java.util.zip.Checksum;

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

 * limitations under the License.
 */

package com.google.common.io;

/**
 * Options controlling the behavior of sources/sinks/streams for testing.
 *
 * @author Colin Decker
 */
public enum TestOption {
  OPEN_THROWS,
  SKIP_THROWS,
  READ_THROWS,
  WRITE_THROWS,
  CLOSE_THROWS,
  AVAILABLE_ALWAYS_ZERO

 * limitations under the License.
 */

package com.google.common.io;

/**
 * Options controlling the behavior of sources/sinks/streams for testing.
 *
 * @author Colin Decker
 */
public enum TestOption {
  OPEN_THROWS,
  SKIP_THROWS,
  READ_THROWS,
  WRITE_THROWS,
  CLOSE_THROWS,
  AVAILABLE_ALWAYS_ZERO

 * Interface for a supplier of streams that can report whether a stream was opened and whether that
 * stream was closed. Intended for use in a test where only a single stream should be opened and
 * possibly closed.
 *
 * @author Colin Decker
 */
public interface TestStreamSupplier {

  /** Returns whether or not a new stream was opened. */
  boolean wasStreamOpened();

  /** Returns whether or not an open stream was closed. */

import com.google.common.annotations.J2ktIncompatible;

/**
 * Modes for opening a file for writing. The default when mode when none is specified is to truncate
 * the file before writing.
 *
 * @author Colin Decker
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public enum FileWriteMode {
  /** Specifies that writes to the opened file should append to the end of the file. */
  APPEND