This file is the source of truth for each `version` at rest. `xl.meta` is a msgpack file serialized from a
well defined data structure. To understand `xl.meta` here are the few things to start with

`xl.meta` carries first 8 bytes an XL header which describes the current format and the format version,
allowing the unmarshaller's to automatically use the right data structures to parse the subsequent content in the stream.

### v1.0

  /** The [Buffer] of [sink]. Write to this and then flush/emit [sink]. */
  private val sinkBuffer: Buffer = sink.buffer
  private var writerClosed = false

  /** Lazily initialized on first use. */
  private var messageDeflater: MessageDeflater? = null

  // Masks are only a concern for client writers.
  private val maskKey: ByteArray? = if (isClient) ByteArray(4) else null

   * first pre-determined printing line on the next form or page. (Applicable also to display
   * devices.)
   *
   * @since 8.0
   */
  public static final byte FF = 12;

  /**
   * Carriage Return ('\r'): A format effector which controls the movement of the printing position

## Install `SQLModel` { #install-sqlmodel }

First, make sure you create your [virtual environment](../virtual-environments.md), activate it, and then install `sqlmodel`:

<div class="termy">

```console
$ pip install sqlmodel
---> 100%
```

</div>

## Create the App with a Single Model { #create-the-app-with-a-single-model }

We'll create the simplest first version of the app with a single **SQLModel** model first.

	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		tc, ok := r.Context().Value(mcontext.ContextTraceKey).(*mcontext.TraceCtxt)

		// Reject unsupported reserved metadata first before validation.
		if containsReservedMetadata(r.Header) {
			if ok {
				tc.FuncName = "handler.ValidRequest"
				tc.ResponseRecorder.LogErrBody = true
			}

     * be set.
     */

    public static final int P_NODE = 1;

    /**
     * Try Broadcast queries first, then try to resolve the name using the
     * nameserver.
     */

    public static final int M_NODE = 2;

    /**
     * A Hybrid node tries to resolve a name using the nameserver first. If
     * that fails use the broadcast address. This is the default if a nameserver

     * specified through this <code>jcifs.properties</code> system property.
     *
     * @return a global context, initialized on first call
     */
    public static synchronized final SingletonContext getInstance() {
        if (INSTANCE == null) {
            try {
                log.debug("Initializing singleton context");
                init(null);

                (byte) 0x05, (byte) 0x06, (byte) 0x07, (byte) 0x08
              },
              0x89abcdef,
              0x0123456789abcdefL, // asInt/asLong as above, due to equal eight first bytes
              "efcdab89674523010102030405060708"),
          new ExpectedHashCode(
              new byte[] {(byte) 0xdf, (byte) 0x9b, (byte) 0x57, (byte) 0x13},
              0x13579bdf,
              null,

 *       to close resources will be thrown from the finally block. The throwable from the try block
 *       will be thrown.
 *   <li>If no exceptions or errors were thrown in the try block, the <i>first</i> exception thrown
 *       by an attempt to close a resource will be thrown.
 *   <li>Any exception caught when attempting to close a resource that is <i>not</i> thrown (because

	policyDBGroupsListKey   = "policydb/groups/"
)

func findSecondIndex(s string, substr string) int {
	first := strings.Index(s, substr)
	if first == -1 {
		return -1
	}
	second := strings.Index(s[first+1:], substr)
	if second == -1 {
		return -1
	}
	return first + second + 1
}

// splitPath splits a path into a top-level directory and a child item. The