OutputStream nos = ByteStreams.nullOutputStream();
    // write to the output stream
    nos.write('n');
    String test = "Test string for NullOutputStream";
    byte[] bytes = test.getBytes(US_ASCII);
    nos.write(bytes);
    nos.write(bytes, 2, 10);
    nos.write(bytes, bytes.length - 5, 5);
    // nothing really to assert?
    assertThat(ByteStreams.nullOutputStream()).isSameInstanceAs(ByteStreams.nullOutputStream());

    OutputStream nos = ByteStreams.nullOutputStream();
    // write to the output stream
    nos.write('n');
    String test = "Test string for NullOutputStream";
    byte[] bytes = test.getBytes(US_ASCII);
    nos.write(bytes);
    nos.write(bytes, 2, 10);
    nos.write(bytes, bytes.length - 5, 5);
    // nothing really to assert?
    assertThat(ByteStreams.nullOutputStream()).isSameInstanceAs(ByteStreams.nullOutputStream());

        }

        @Override
        public String toString() {
          return "ByteStreams.nullOutputStream()";
        }
      };

  /**
   * Returns an {@link OutputStream} that simply discards written bytes.
   *
   * <p><b>Java 11+ users:</b> use {@link OutputStream#nullOutputStream()} instead. Note that the
   * {@link ByteStreams} method returns a singleton stream whose {@code close} method has no effect,

    assertArrayEquals(expected, slice.read());
  }

  public void testCopyToStream_doesNotCloseThatStream() throws IOException {
    TestOutputStream out = new TestOutputStream(ByteStreams.nullOutputStream());
    assertFalse(out.closed());
    source.copyTo(out);
    assertFalse(out.closed());
  }

  public void testClosesOnErrors_copyingToByteSinkThatThrows() {

    assertArrayEquals(expected, slice.read());
  }

  public void testCopyToStream_doesNotCloseThatStream() throws IOException {
    TestOutputStream out = new TestOutputStream(ByteStreams.nullOutputStream());
    assertFalse(out.closed());
    source.copyTo(out);
    assertFalse(out.closed());
  }

  public void testClosesOnErrors_copyingToByteSinkThatThrows() {

    private static final NullByteSink INSTANCE = new NullByteSink();

    @Override
    public OutputStream openStream() {
      return ByteStreams.nullOutputStream();
    }
  }

  // Compare by toString() to satisfy 2 properties:
  // 1. compareTo(null) should throw NullPointerException
  // 2. the order is deterministic and easy to understand, for debugging purpose.

    private static final NullByteSink INSTANCE = new NullByteSink();

    @Override
    public OutputStream openStream() {
      return ByteStreams.nullOutputStream();
    }
  }

  // Compare by toString() to satisfy 2 properties:
  // 1. compareTo(null) should throw NullPointerException
  // 2. the order is deterministic and easy to understand, for debugging purpose.