# https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-metadata.html
exit_if_not_on_ec2_instance() {
  curl -m 1 -s "http://169.254.169.254/latest/meta-data/instance-id"
  IS_EC2_INSTANCE=$?
  if [ $IS_EC2_INSTANCE -ne 0 ]; then
    echo "Not running on an EC2 instance, skipping the configuration"
    exit 0
  fi
}

But we want to be able to parameterize that fixed content.

## A "callable" instance { #a-callable-instance }

In Python there's a way to make an instance of a class a "callable".

Not the class itself (which is already a callable), but an instance of that class.

To do that, we declare a method `__call__`:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[12] *}

    instance := grid.NewStream[*Payload, *Req, *Resp](h, newPayload, newReq, newResp)

    // Tweakable options
    instance.WithPayload = true // default true when newPayload != nil
    instance.OutCapacity = 1    // default
    instance.InCapacity = 1     // default true when newReq != nil

    // Register the handler on the manager
    instance.Register(manager, handler, "asubroute")

## Crear una instance { #create-an-instance }

Podríamos crear una instance de esta clase con:

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[18] *}

Y de esa manera podemos "parametrizar" nuestra dependencia, que ahora tiene `"bar"` dentro de ella, como el atributo `checker.fixed_content`.

## Usar la instance como una dependencia { #use-the-instance-as-a-dependency }

  public void testToString() {
    assertEquals("{}", INSTANCE.toString());
  }

  public void testSize() {
    assertEquals(0, INSTANCE.size());
  }

  public void testGet() {
    assertThat(INSTANCE.get('a', 1)).isNull();
  }

  public void testIsEmpty() {
    assertTrue(INSTANCE.isEmpty());
  }

  public void testCellSet() {
    assertEquals(ImmutableSet.of(), INSTANCE.cellSet());
  }

    /**
     * Creates a new XmlNode instance with the specified name.
     *
     * @param name the name for the new node
     * @return a new XmlNode instance
     * @throws NullPointerException if name is null
     */
    static XmlNode newInstance(String name) {
        return newBuilder().name(name).build();
    }

    /**
     * Creates a new XmlNode instance with the specified name and value.
     *

        "/wrapped-class-instance-dependency/",
        "/wrapped-class-instance-async-dependency/",
        "/wrapped-class-instance-gen-dependency/",
        "/wrapped-class-instance-async-gen-dependency/",
        "/class-instance-wrapped-dependency/",
        "/class-instance-wrapped-async-dependency/",
        "/class-instance-async-wrapped-dependency/",
        "/class-instance-async-wrapped-async-dependency/",

    for (queue in TaskRunner.INSTANCE.activeQueues()) {
      // We wait at most 1 second, so we don't ever turn multiple lost threads into
      // a test timeout failure.
      val waitTime = (entryTime + 1_000_000_000L - System.nanoTime())
      if (!queue.idleLatch().await(waitTime, TimeUnit.NANOSECONDS)) {
        TaskRunner.INSTANCE.withLock {
          TaskRunner.INSTANCE.cancelAll()
        }

  internal val delegate: RealConnectionPool,
) {
  internal constructor(
    maxIdleConnections: Int = 5,
    keepAliveDuration: Long = 5,
    timeUnit: TimeUnit = TimeUnit.MINUTES,
    taskRunner: TaskRunner = TaskRunner.INSTANCE,
    connectionListener: ConnectionListener = ConnectionListener.NONE,
  ) : this(
    RealConnectionPool(
      taskRunner = taskRunner,
      maxIdleConnections = maxIdleConnections,

			Help:    "Time taken by requests served by current MinIO server instance",
			Buckets: []float64{.05, .1, .25, .5, 1, 2.5, 5, 10},
		},
		[]string{"api"},
	)
	bucketHTTPRequestsDuration = prometheus.NewHistogramVec(
		prometheus.HistogramOpts{
			Name:    "s3_ttfb_seconds",
			Help:    "Time taken by requests served by current MinIO server instance per bucket",
			Buckets: []float64{.05, .1, .25, .5, 1, 2.5, 5, 10},
		},