assertEquals(written, counter.getCount());

    counter.write(0);
    written += 1;
    assertEquals(written, out.size());
    assertEquals(written, counter.getCount());

    byte[] data = new byte[10];
    counter.write(data);
    written += 10;
    assertEquals(written, out.size());
    assertEquals(written, counter.getCount());

    counter.write(data, 0, 5);
    written += 5;
    assertEquals(written, out.size());

        cos.write(new byte[] { 0, 1, 2, 3, 4 });
        assertFalse(cos.done);
        assertTrue(cos.isInMemory());
        cos.close();
        assertFalse(cos.done);
    }

    @Test
    public void inFile() throws IOException {
        ContentOutputStream cos = new ContentOutputStream(10, Curl.tmpDir);
        cos.write(new byte[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 });

### Threads

#### Application's calling thread

The application-layer must block on writing I/O. We can't return from a write until we've pushed its bytes onto the socket. Otherwise, if the write fails we are unable to deliver its IOException to the application. We would have told the application layer that the write succeeded, but it didn't!

        }
    }

    private void write(Path metadataPath, Metadata metadata) throws RepositoryException {
        try {
            Files.createDirectories(metadataPath.getParent());
            try (OutputStream output = Files.newOutputStream(metadataPath)) {
                new MetadataStaxWriter().write(output, metadata.getDelegate());
            }

func (z *healingTracker) EncodeMsg(en *msgp.Writer) (err error) {
	// map header, size 29
	// write "ID"
	err = en.Append(0xde, 0x0, 0x1d, 0xa2, 0x49, 0x44)
	if err != nil {
		return
	}
	err = en.WriteString(z.ID)
	if err != nil {
		err = msgp.WrapError(err, "ID")
		return
	}
	// write "PoolIndex"
	err = en.Append(0xa9, 0x50, 0x6f, 0x6f, 0x6c, 0x49, 0x6e, 0x64, 0x65, 0x78)
	if err != nil {

     * Pipe instance although this is not a requirement (e.g. a
     * read-only named pipe would write data to this stream on
     * connection). Reading from this stream may block. Therefore it
     * may be necessary that an addition thread be used to read and
     * write to a Named Pipe.
     */

    public InputStream getNamedPipeInputStream() throws IOException {
        if( pipeIn == null ) {

  fun connectionPreface() {
    this.withLock {
      if (closed) throw IOException("closed")
      if (!client) return // Nothing to write; servers don't send connection headers!
      if (logger.isLoggable(FINE)) {
        logger.fine(format(">> CONNECTION ${CONNECTION_PREFACE.hex()}"))
      }
      sink.write(CONNECTION_PREFACE)
      sink.flush()
    }
  }

  /** Applies `peerSettings` and then sends a settings ACK. */

	}
}

type teststringwriter struct {
	write       string
	writeString string
}

func (w *teststringwriter) Write(b []byte) (int, error) {
	w.write += string(b)
	return len(b), nil
}

func (w *teststringwriter) WriteString(s string) (int, error) {
	w.writeString += s
	return len(s), nil
}

func (w *teststringwriter) check(t *testing.T, write, writeString string) {
	t.Helper()

  public void testWriteString() throws IOException {
    File temp = createTempFile();
    Files.write(I18N, temp, UTF_16LE);
    assertEquals(I18N, Files.toString(temp, UTF_16LE));
  }

  public void testWriteBytes() throws IOException {
    File temp = createTempFile();
    byte[] data = newPreFilledByteArray(2000);
    Files.write(data, temp);
    assertTrue(Arrays.equals(data, Files.toByteArray(temp)));

	}
	// write "id"
	err = en.Append(0xa2, 0x69, 0x64)
	if err != nil {
		return
	}
	err = en.WriteString(z.id)
	if err != nil {
		err = msgp.WrapError(err, "id")
		return
	}
	// write "err"
	err = en.Append(0xa3, 0x65, 0x72, 0x72)
	if err != nil {
		return
	}
	err = en.WriteString(z.error)
	if err != nil {
		err = msgp.WrapError(err, "error")
		return
	}
	// write "root"