checkNotDone();
      checkNotNull(bytes);
      mac.update(bytes);
    }

    private void checkNotDone() {
      checkState(!done, "Cannot re-use a Hasher after calling hash() on it");
    }

    @Override
    public HashCode hash() {
      checkNotDone();
      done = true;
      return HashCode.fromBytesNoCopy(mac.doFinal());
    }
  }

 * 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

  public static boolean equal(@CheckForNull Object a, @CheckForNull Object b) {
    return a == b || (a != null && a.equals(b));
  }

  /**
   * Generates a hash code for multiple values. The hash code is generated by calling {@link
   * Arrays#hashCode(Object[])}. Note that array arguments to this method, with the exception of a
   * single Object array, do not get any special handling; their hash codes are based on identity
   * and not contents.

    assertFalse(
        "multiset.entrySet() contains a non-entry", getMultiset().entrySet().contains(e0()));
  }

  public void testEntrySet_twice() {
    assertEquals(
        "calling multiset.entrySet() twice returned unequal sets",
        getMultiset().entrySet(),
        getMultiset().entrySet());
  }

  @CollectionSize.Require(ZERO)
  public void testEntrySet_hashCode_size0() {

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

import java.io.ByteArrayInputStream;
import java.io.FilterReader;
import java.io.IOException;
import java.io.InputStreamReader;

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

  private final TestInputStream in;

  public TestReader(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 com.google.common.collect.ImmutableSet;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Arrays;

/** @author Colin Decker */
public class TestOutputStream extends FilterOutputStream {

  private final ImmutableSet<TestOption> options;
  private boolean closed;

import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.TimeUnit;
import junit.framework.TestCase;

/**
 * Tests for {@link AbstractListeningExecutorService}.
 *
 * @author Colin Decker
 */
public class AbstractListeningExecutorServiceTest extends TestCase {

  public void testSubmit() throws Exception {
    /*
     * Mostly just tests that TrustedListenableFutureTask are created and run; tests for

import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

/**
 * A ScheduledExecutorService that executes all scheduled actions immediately in the calling thread.
 *
 * <p>See {@link TestingExecutors#sameThreadScheduledExecutor()} for a full list of constraints.
 *
 * @author John Sirois
 * @author Zach van Schouwen
 */
@GwtIncompatible

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.EnumSet;

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

  private final byte[] bytes = newPreFilledByteArray(10000);

  private TestByteSink sink;

  @Override
  protected void setUp() throws Exception {