*
 * @author Bin Zhu
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
class MultiReader extends Reader {
  private final Iterator<? extends CharSource> it;
  @CheckForNull private Reader current;

  MultiReader(Iterator<? extends CharSource> readers) throws IOException {
    this.it = readers;
    advance();
  }

	}
	header[0] = Version
	binary.LittleEndian.PutUint32(header[1:], uint32(len(metadata)))
	buffer.Write(header[:])
	buffer.Write(metadata)

	return io.MultiReader(
		&buffer,
		stream.EncryptReader(plaintext, nonce, nil),
	), nil
}

// Decrypt decrypts the ciphertext using a key managed by the KMS.
// The same context that have been used during encryption must be

    ConcatenatedCharSource(Iterable<? extends CharSource> sources) {
      this.sources = checkNotNull(sources);
    }

    @Override
    public Reader openStream() throws IOException {
      return new MultiReader(sources.iterator());
    }

    @Override
    public boolean isEmpty() throws IOException {
      for (CharSource source : sources) {
        if (!source.isEmpty()) {
          return false;
        }

	}
}

func TestReadZero(t *testing.T) {
	for _, size := range []int{100, 2} {
		t.Run(fmt.Sprintf("bufsize=%d", size), func(t *testing.T) {
			r := io.MultiReader(strings.NewReader("abc"), &emptyThenNonEmptyReader{r: strings.NewReader("def"), n: 1})
			br := NewReaderSize(r, size)
			want := func(s string, wantErr error) {
				p := make([]byte, 50)
				n, err := br.Read(p)

		cumulativeSum := int64(0)
		for _, p := range oi.partLengths {
			readers = append(readers, NewDummyDataGen(p, cumulativeSum))
			cumulativeSum += p
		}

		refReader := io.LimitReader(ioutilx.NewSkipReader(io.MultiReader(readers...), off), length)
		if ok, msg := cmpReaders(refReader, rec.Body); !ok {
			t.Fatalf("(%s) Object: %s Case %d ByteRange: %s --> data mismatch! (msg: %s)", instanceType, oi.objectName, i+1, byteRange, msg)
		}
	}