*     {@code double}) in the proper order.
   */
  private void writeObject(ObjectOutputStream s) throws IOException {
    s.defaultWriteObject();

    // Write out array length
    int length = length();
    s.writeInt(length);

    // Write out all elements in the proper order.
    for (int i = 0; i < length; i++) {
      s.writeDouble(get(i));
    }
  }

        sip := siphash.New(id[:])
        sip.Write([]byte(key))
        return int(sip.Sum64() % uint64(cardinality))
}
```

Input for the key is the object name specified in `PutObject()`, returns a unique index. This index is one of the erasure sets where the object will reside. This function is a consistent hash for a given object name i.e for a given object name the index returned is always the same.

        byte[] hdr = new byte[64]; // SMB2 header is 64 bytes
        System.arraycopy(SMBUtil.SMB2_HEADER, 0, hdr, 0, 64);
        // Write Status (little-endian) at offset 8 in the SMB2 header
        SMBUtil.writeInt4(status, hdr, 8);
        // Write Command = SMB2_IOCTL (0x000B) at offset 12
        SMBUtil.writeInt2(0x000B, hdr, 12);
        // Mark as server response to be realistic (optional)

     * file attributes such as ACLs but it does copy regular attributes as
     * well as create and last write times. This method is almost twice as
     * efficient as manually copying as it employs an additional write
     * thread to read and write data concurrently.
     * <br>
     * It is not possible (nor meaningful) to copy entire workgroups or
     * servers.
     *
     * @param dest

        // Note: Due to bug in line 96 (commented out bufferIndex = bufferOffset),
        // the decode starts at bufferIndex=8 instead of dataOffset=80
        // So we need to write data at bufferIndex=8

        // Write first FileBothDirectoryInfo at bufferIndex=8
        SMBUtil.writeInt4(104, buffer, 8); // NextEntryOffset to second entry
        SMBUtil.writeInt4(0, buffer, 12); // FileIndex

	return &exitCodeFilter{w: w, exitRe: exitRe}, exitStr
}

func (f *exitCodeFilter) Write(data []byte) (int, error) {
	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 {

 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package jcifs.internal.smb2.rdma;

import jcifs.internal.util.SMBUtil;

/**
 * SMB2 RDMA Transform structure for READ/WRITE channel info.
 *
 * As per MS-SMB2 2.2.13.1.1 and 2.2.21.1.1
 */
public class Smb2RdmaTransform {

          throw ProtocolException("unexpected address: " + toSocket.localAddress)
        }

        // Write the reply.
        fromSink.writeByte(VERSION_5)
        fromSink.writeByte(REPLY_SUCCEEDED)
        fromSink.writeByte(0)
        fromSink.writeByte(ADDRESS_TYPE_IPV4)
        fromSink.write(localAddress)
        fromSink.writeShort(toSocket.localPort)
        fromSink.emit()

	setEventStreamHeaders(w)

	// Listen Publisher and peer-listen-client uses nonblocking send and hence does not wait for slow receivers.
	// Use buffered channel to take care of burst sends or slow w.Write()
	mergeCh := make(chan []byte, globalAPIConfig.getRequestsPoolCapacity()*len(globalEndpoints.Hostnames()))
	localCh := make(chan event.Event, globalAPIConfig.getRequestsPoolCapacity())

It is just a standard function that can receive parameters.

It can be an `async def` or normal `def` function, **FastAPI** will know how to handle it correctly.

In this case, the task function will write to a file (simulating sending an email).

And as the write operation doesn't use `async` and `await`, we define the function with normal `def`:

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}