// Setup
    File file = createTempFile();
    Files.write(bytes, file);

    // Test
    MappedByteBuffer actual = Files.map(file);

    // Verify
    ByteBuffer expected = ByteBuffer.wrap(bytes);
    assertTrue("ByteBuffers should be equal.", expected.equals(actual));
  }

  public void testMap_noSuchFile() throws IOException {
    // Setup
    File file = createTempFile();

 *       value was available
 *   <li>To distinguish between "unknown" (for example, not present in a map) and "known to have no
 *       value" (present in the map, with value {@code Optional.absent()})
 *   <li>To wrap nullable references for storage in a collection that does not support {@code null}
 *       (though there are <a
 *       href="https://github.com/google/guava/wiki/LivingWithNullHostileCollections">several other

 * views are modifiable.
 *
 * <p>This class is not threadsafe when any concurrent operations update the multimap. Concurrent
 * read operations will work correctly. To allow concurrent update operations, wrap your multimap
 * with a call to {@link Multimaps#synchronizedSetMultimap}.
 *
 * <p><b>Warning:</b> Do not modify either a key <i>or a value</i> of a {@code LinkedHashMultimap}

 * views are modifiable.
 *
 * <p>This class is not threadsafe when any concurrent operations update the multimap. Concurrent
 * read operations will work correctly. To allow concurrent update operations, wrap your multimap
 * with a call to {@link Multimaps#synchronizedSetMultimap}.
 *
 * <p><b>Warning:</b> Do not modify either a key <i>or a value</i> of a {@code LinkedHashMultimap}

    byte[] murmur3Hash = Hashing.murmur3_32().hashLong(42L).asBytes();
    byte[] combined = new byte[md5Hash.length + murmur3Hash.length];
    ByteBuffer buffer = ByteBuffer.wrap(combined);
    buffer.put(md5Hash);
    buffer.put(murmur3Hash);
    HashCode expected = HashCode.fromBytes(combined);

    assertEquals(

   *
   * If the hint is unknown [chooser] should return null which will cause the value to be decoded as
   * an opaque byte string.
   *
   * This may optionally wrap the contents in a tag.
   */
  fun usingTypeHint(chooser: (Any?) -> DerAdapter<*>?): DerAdapter<Any?> {
    return object : DerAdapter<Any?> {
      override fun matches(header: DerHeader): Boolean = true

func diskHealthReader(ctx context.Context, r io.Reader) io.Reader {
	// Check if context has a disk health check.
	tracker, ok := ctx.Value(healthDiskCtxKey{}).(*healthDiskCtxValue)
	if !ok {
		// No need to wrap
		return r
	}
	return &diskHealthWrapper{r: r, tracker: tracker}
}

// diskHealthWriter provides a wrapper that will update disk health on
// ctx, on every successful write.

		wantEncryption := crypto.Requested(r.Header)
		s2c, cb := newS2CompressReader(reader, actualSize, wantEncryption)
		dstOpts.IndexCB = cb
		defer s2c.Close()
		reader = etag.Wrap(s2c, reader)
		length = -1
	} else {
		delete(srcInfo.UserDefined, ReservedMetadataPrefix+"compression")
		delete(srcInfo.UserDefined, ReservedMetadataPrefix+"actual-size")
		reader = gr
	}

	b := NewReaderSize(strings.NewReader("hello world"), BufSize)
	// Does it recognize itself?
	b1 := NewReaderSize(b, BufSize)
	if b1 != b {
		t.Error("NewReaderSize did not detect underlying Reader")
	}
	// Does it wrap if existing buffer is too small?
	b2 := NewReaderSize(b, 2*BufSize)
	if b2 == b {
		t.Error("NewReaderSize did not enlarge buffer")
	}
}

func TestNewWriterSizeIdempotent(t *testing.T) {

 *       value was available
 *   <li>To distinguish between "unknown" (for example, not present in a map) and "known to have no
 *       value" (present in the map, with value {@code Optional.absent()})
 *   <li>To wrap nullable references for storage in a collection that does not support {@code null}
 *       (though there are <a
 *       href="https://github.com/google/guava/wiki/LivingWithNullHostileCollections">several other