source.copyTo(out);
    assertExpectedBytes(out.toByteArray());
  }

  public void testCopyTo_byteSink() throws IOException {
    final ByteArrayOutputStream out = new ByteArrayOutputStream();
    // HERESY! but it's ok just for this I guess
    source.copyTo(
        new ByteSink() {
          @Override
          public OutputStream openStream() throws IOException {
            return out;
          }

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

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

import com.google.common.collect.SortedMapDifference;
import com.google.common.collect.SortedMultiset;
import com.google.common.collect.SortedSetMultimap;
import com.google.common.collect.Table;
import com.google.common.io.ByteSink;
import com.google.common.io.ByteSource;
import com.google.common.io.CharSink;
import com.google.common.io.CharSource;
import com.google.common.primitives.UnsignedInteger;
import com.google.common.primitives.UnsignedLong;

import com.google.common.collect.SortedMapDifference;
import com.google.common.collect.SortedMultiset;
import com.google.common.collect.SortedSetMultimap;
import com.google.common.collect.Table;
import com.google.common.io.ByteSink;
import com.google.common.io.ByteSource;
import com.google.common.io.CharSink;
import com.google.common.io.CharSource;
import com.google.common.primitives.UnsignedInteger;
import com.google.common.primitives.UnsignedLong;

   * will append to the end of the file without truncating it.
   *
   * @since 14.0
   */
  public static ByteSink asByteSink(File file, FileWriteMode... modes) {
    return new FileByteSink(file, modes);
  }

  private static final class FileByteSink extends ByteSink {

    private final File file;
    private final ImmutableSet<FileWriteMode> modes;

  public abstract OutputStream encodingStream(Writer writer);

  /**
   * Returns a {@code ByteSink} that writes base-encoded bytes to the specified {@code CharSink}.
   */
  @J2ktIncompatible
  @GwtIncompatible // ByteSink,CharSink
  public final ByteSink encodingSink(CharSink encodedSink) {
    checkNotNull(encodedSink);
    return new ByteSink() {
      @Override
      public OutputStream openStream() throws IOException {

    private final byte[] initialBytes;

    private FileByteSinkFactory(byte @Nullable [] initialBytes) {
      this.initialBytes = initialBytes;
    }

    @Override
    public ByteSink createSink() throws IOException {
      File file = createFile();
      if (initialBytes != null) {
        FileOutputStream out = new FileOutputStream(file);
        try {
          out.write(initialBytes);

    }
  }

  /**
   * Copies the contents of this byte source to the given {@code ByteSink}.
   *
   * @return the number of bytes copied
   * @throws IOException if an I/O error occurs while reading from this source or writing to {@code
   *     sink}
   */
  @CanIgnoreReturnValue
  public long copyTo(ByteSink sink) throws IOException {
    checkNotNull(sink);

    Closer closer = Closer.create();