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 }

                afterExecutionFailure.incrementAndGet();
            }
        };
        assertSame(instance, scope.scope(Key.get(Object.class), () -> instance).get());
        assertSame(
                instance,
                scope.scope(Key.get(WeakMojoExecutionListener.class), () -> instance)
                        .get());

        final MojoExecutionEvent event = new MojoExecutionEvent(null, null, null, null);

          .put(ImmutableClassToInstanceMap.class, ImmutableClassToInstanceMap.builder().build())
          .put(Comparable.class, ByToString.INSTANCE)
          .put(Comparator.class, AlwaysEqual.INSTANCE)
          .put(Ordering.class, AlwaysEqual.INSTANCE)
          .put(Range.class, Range.all())
          .put(MapDifference.class, Maps.difference(ImmutableMap.of(), ImmutableMap.of()))
          .put(

  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());
  }

        "/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/",

class MonotonicClockTest {

    @Test
    @DisplayName("MonotonicClock singleton instance should always return the same instance")
    void testSingletonInstance() {
        MonotonicClock clock1 = MonotonicClock.get();
        MonotonicClock clock2 = MonotonicClock.get();

        assertSame(clock1, clock2, "Multiple calls to get() should return the same instance");
    }

    @Test

# 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
}

  public <E extends Comparable<?>> E min(E a, E b) {
    return NaturalOrdering.INSTANCE.max(a, b);
  }

  @Override
  public <E extends Comparable<?>> E min(E a, E b, E c, E... rest) {
    return NaturalOrdering.INSTANCE.max(a, b, c, rest);
  }

  @Override
  public <E extends Comparable<?>> E min(Iterator<E> iterator) {
    return NaturalOrdering.INSTANCE.max(iterator);
  }

  @Override