return CharBuffer.allocate(DEFAULT_BUF_SIZE);
  }

  private CharStreams() {}

  /**
   * Copies all characters between the {@link Readable} and {@link Appendable} objects. Does not
   * close or flush either object.
   *
   * @param from the object to read from
   * @param to the object to write to
   * @return the number of characters copied
   * @throws IOException if an I/O error occurs
   */

	n := len(data)
	f.buf.Write(data)
	// Flush to w until a potential match of exitRe
	b := f.buf.Bytes()
	match := f.exitRe.FindIndex(b)
	if match == nil {
		// Flush all of the buffer.
		_, err := f.w.Write(b)
		f.buf.Reset()
		if err != nil {
			return n, err
		}
	} else {
		// Flush up to the beginning of the (potential) match.
		_, err := f.w.Write(b[:match[0]])

            SmbFile file = ref.get();
            if (file != null) {
                try {
                    // Force flush any buffered writes
                    // This would typically call file's internal flush method
                    // For now, we log the action as the actual implementation
                    // depends on SmbFile's internal caching mechanism
                    log.info("Flushed write cache for: {}", path);

        // flush() should work with in-memory data
        ContentOutputStream cos = new ContentOutputStream(10, Curl.tmpDir);
        cos.write(new byte[] { 0, 1, 2 });
        cos.flush();
        assertTrue(cos.isInMemory());
        cos.close();
    }

    @Test
    public void testFlushInFile() throws IOException {
        // flush() should work with file-based data

	if w.cw.count != 0 {
		panic("zip: SetOffset called after data was written")
	}
	w.cw.count = n
}

// Flush flushes any buffered data to the underlying writer.
// Calling Flush is not normally necessary; calling Close is sufficient.
func (w *Writer) Flush() error {
	return w.cw.w.(*bufio.Writer).Flush()
}

// SetComment sets the end-of-central-directory comment field.
// It can only be called before [Writer.Close].

  public void close() throws IOException {
    try {
      state.close();
    } finally {
      reachabilityFence(byteSource);
    }
  }

  @Override
  public void flush() throws IOException {
    try {
      state.flush();
    } finally {
      reachabilityFence(byteSource);
    }
  }

  /**
   * Per-instance state, extracted to a separate object so that {@link FinalizableReference} can

      }
    }

    @Throws(IOException::class)
    override fun flush() {
      assertLockNotHeld()

      withLock {
        checkOutNotClosed()
      }
      // TODO(jwilson): flush the connection?!
      while (sendBuffer.size > 0L) {
        emitFrame(false)
        connection.flush()
      }
    }

    override fun timeout(): Timeout = writeTimeout

      "Trailers cannot be read because the state is $state"
    }
    return trailers
  }

  override fun flushRequest() {
    socket.sink.flush()
  }

  override fun finishRequest() {
    socket.sink.flush()
  }

  /** Returns bytes of a request header for sending on an HTTP transport. */
  fun writeRequest(
    headers: Headers,
    requestLine: String,
  ) {

	io.Writer
	fileState

	ReadFrom(io.Reader) (int64, error)
}

// Flush finishes writing the current file's block padding.
// The current file must be fully written before Flush can be called.
//
// This is unnecessary as the next call to [Writer.WriteHeader] or [Writer.Close]
// will implicitly flush out the file's padding.
func (tw *Writer) Flush() error {
	if tw.err != nil {
		return tw.err
	}

      cleanupQueue.schedule(cleanupTask)
      return null
    }

    // Flush the journal before creating files to prevent file leaks.
    val journalWriter = this.journalWriter!!
    journalWriter
      .writeUtf8(DIRTY)
      .writeByte(' '.code)
      .writeUtf8(key)
      .writeByte('\n'.code)
    journalWriter.flush()

    if (hasJournalErrors) {