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() {

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

  /**
   * Returns an {@link OutputStream} that simply discards written bytes.
   *
   * @since 14.0 (since 1.0 as com.google.common.io.NullOutputStream)
   */
  public static OutputStream nullOutputStream() {
    return NULL_OUTPUT_STREAM;
  }

  /**

    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.